Tests: the keyword-list test lets the list settle before clicking rows

keyword_list_filters_renames_and_suggests failed on FreeBSD CI (b35487a) and
locally (2 of 13 runs under load): ui.clickWidget clicks last frame's rect,
and right after opening the panel / expanding "travel" the rows could still
move, so the click hit "sunrise" instead of "travel|italy". Settling first:
30 of 30 runs pass.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

.github/workflows/freebsd.yml

@@ -27,6 +27,12 @@ jobs:
     timeout-minutes: 300
     steps:
       - uses: actions/checkout@v4
+      # Optional font build input, so the Japanese font tests run (they skip without it).
+      - uses: actions/checkout@11d5960a326750d5838078e36cf38b85af677262 # v4
+        with:
+          repository: storytold/craft-fonts
+          ref: abb83316d96aa59c1cf64784289e378fe9fa5695
+          path: craft-fonts
       - name: Build and test in a FreeBSD VM
         uses: vmactions/freebsd-vm@c46abacb49f09938ca4e1702d15d836285d694cc # v1
         with:
@@ -44,5 +50,6 @@ jobs:
             # The checkout is synced in under another owner; let tests that call git read it.
             git config --global --add safe.directory "*"
             rustc --version
+            export CRAFT_FONTS_DIR="$PWD/craft-fonts" CRAFT_FONTS_REQUIRED=1
             CARGO_PROFILE_DEV_DEBUG=0 cargo build --workspace --all-targets --locked
             CARGO_PROFILE_DEV_DEBUG=0 cargo test --workspace --locked

.github/workflows/packaging-lint.yml

@@ -47,6 +47,10 @@ jobs:
       - name: XML, desktop entry, AppStream, Flatpak manifest
         run: |
           xmllint --noout packaging/windows/lightcraft.wxs packaging/macos/*.plist* packaging/linux/*.xml*
+          # Windows Installer needs Icon ids ending in .ico or .exe, or shortcuts show a blank icon.
+          if grep -oE '<Icon Id="[^"]*"' packaging/windows/lightcraft.wxs | grep -vE '\.(ico|exe)"$'; then
+            echo "::error::Icon Id must end in .ico or .exe"; exit 1
+          fi
           desktop-file-validate packaging/linux/ai.storyteller.lightcraft.desktop
           sed -e 's/@VERSION@/0.0.0/' -e 's/@DATE@/2026-01-01/' packaging/linux/ai.storyteller.lightcraft.metainfo.xml.in >"$RUNNER_TEMP/ai.storyteller.lightcraft.metainfo.xml"
           appstreamcli validate --no-net --explain "$RUNNER_TEMP/ai.storyteller.lightcraft.metainfo.xml"

.github/workflows/release.yml

@@ -70,6 +70,12 @@ jobs:
       LIGHTCRAFT_BUILD_DATE: ${{ needs.version.outputs.date }}
     steps:
       - uses: actions/checkout@v4
+      # Fonts (optional build input; required for releases): see craftrules standards/fonts.md.
+      - uses: actions/checkout@11d5960a326750d5838078e36cf38b85af677262 # v4
+        with:
+          repository: storytold/craft-fonts
+          ref: abb83316d96aa59c1cf64784289e378fe9fa5695 # bump deliberately
+          path: craft-fonts
       - uses: dtolnay/rust-toolchain@stable
         with:
           targets: aarch64-apple-darwin, x86_64-apple-darwin
@@ -87,6 +93,8 @@ jobs:
         run: packaging/macos/import-cert.sh
       - name: Build, sign, notarize
         env:
+          CRAFT_FONTS_DIR: ${{ github.workspace }}/craft-fonts
+          CRAFT_FONTS_REQUIRED: "1"
           APPLE_ID: ${{ secrets.APPLE_ID }}
           APPLE_PASSWORD: ${{ secrets.APPLE_PASSWORD }}
           APPLE_TEAM_ID: ${{ secrets.APPLE_TEAM_ID }}
@@ -112,11 +120,20 @@ jobs:
         include:
           - { arch: x64, target: x86_64-pc-windows-msvc }
           - { arch: x86, target: i686-pc-windows-msvc }
+          # Windows on ARM: cross-compiled on the x64 runner, so signing and WiX run as above.
+          # .github/workflows/windows-arm64.yml installs and runs it on ARM64 hardware.
+          - { arch: arm64, target: aarch64-pc-windows-msvc }
     env:
       LIGHTCRAFT_VERSION: ${{ needs.version.outputs.version }}
       LIGHTCRAFT_BUILD_DATE: ${{ needs.version.outputs.date }}
     steps:
       - uses: actions/checkout@v4
+      # Fonts (optional build input; required for releases): see craftrules standards/fonts.md.
+      - uses: actions/checkout@11d5960a326750d5838078e36cf38b85af677262 # v4
+        with:
+          repository: storytold/craft-fonts
+          ref: abb83316d96aa59c1cf64784289e378fe9fa5695 # bump deliberately
+          path: craft-fonts
       - uses: dtolnay/rust-toolchain@stable
         with:
           targets: ${{ matrix.target }}
@@ -133,6 +150,8 @@ jobs:
       - name: Build, sign, package
         shell: pwsh
         env:
+          CRAFT_FONTS_DIR: ${{ github.workspace }}/craft-fonts
+          CRAFT_FONTS_REQUIRED: "1"
           WINDOWS_CERTIFICATE: ${{ secrets.WINDOWS_CERTIFICATE }}
           WINDOWS_CERTIFICATE_PASSWORD: ${{ secrets.WINDOWS_CERTIFICATE_PASSWORD }}
           AZURE_TENANT_ID: ${{ secrets.AZURE_TENANT_ID }}
@@ -167,6 +186,12 @@ jobs:
       NFPM_VERSION: 2.47.0
     steps:
       - uses: actions/checkout@v4
+      # Fonts (optional build input; required for releases): see craftrules standards/fonts.md.
+      - uses: actions/checkout@11d5960a326750d5838078e36cf38b85af677262 # v4
+        with:
+          repository: storytold/craft-fonts
+          ref: abb83316d96aa59c1cf64784289e378fe9fa5695 # bump deliberately
+          path: craft-fonts
       - name: Install build and packaging tools
         run: |
           sudo apt-get update
@@ -184,6 +209,9 @@ jobs:
         if: inputs.version != ''
         run: cargo xtask version set "$LIGHTCRAFT_VERSION"
       - name: Build and package (AppImage, deb, rpm, tar.gz)
+        env:
+          CRAFT_FONTS_DIR: ${{ github.workspace }}/craft-fonts
+          CRAFT_FONTS_REQUIRED: "1"
         run: packaging/linux/package.sh
       - name: Check the packages
         run: |
@@ -212,6 +240,12 @@ jobs:
       WASM_BINDGEN_VERSION: 0.2.129
     steps:
       - uses: actions/checkout@v4
+      # Fonts (optional build input; required for releases): see craftrules standards/fonts.md.
+      - uses: actions/checkout@11d5960a326750d5838078e36cf38b85af677262 # v4
+        with:
+          repository: storytold/craft-fonts
+          ref: abb83316d96aa59c1cf64784289e378fe9fa5695 # bump deliberately
+          path: craft-fonts
       - uses: dtolnay/rust-toolchain@stable
         with:
           targets: wasm32-unknown-unknown
@@ -221,13 +255,17 @@ jobs:
       - name: Install wasm-bindgen CLI
         run: |
           # Must match the wasm-bindgen version in Cargo.lock exactly (cargo xtask web checks it).
-          command -v wasm-bindgen >/dev/null && wasm-bindgen --version | grep -q "$WASM_BINDGEN_VERSION" \
-            || cargo install wasm-bindgen-cli --version "$WASM_BINDGEN_VERSION" --locked
+          if ! { command -v wasm-bindgen >/dev/null && wasm-bindgen --version | grep -q "$WASM_BINDGEN_VERSION"; }; then
+            cargo install wasm-bindgen-cli --version "$WASM_BINDGEN_VERSION" --locked
+          fi
           wasm-bindgen --version
       - name: Apply version override
         if: inputs.version != ''
         run: cargo xtask version set "$LIGHTCRAFT_VERSION"
       - name: Build and zip
+        env:
+          CRAFT_FONTS_DIR: ${{ github.workspace }}/craft-fonts
+          CRAFT_FONTS_REQUIRED: "1"
         run: packaging/web/package.sh
       - uses: actions/upload-artifact@v4
         with:

.github/workflows/windows-arm64.yml

@@ -0,0 +1,95 @@
+# Windows on ARM: package the ARM64 release the way release.yml does (cross-compiled on an x64
+# runner, unsigned here), then install that MSI on a Windows 11 ARM64 runner, check the installed
+# binaries are ARM64, run the CLI natively, and uninstall. (A native ARM64 `cargo test` job is left
+# out for now: PrintCraft saw an intermittent access violation in egui UI tests there.)
+name: Windows ARM64
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    paths:
+      - Cargo.toml
+      - Cargo.lock
+      - "**/Cargo.toml"
+      - "**/build.rs"
+      - .github/workflows/windows-arm64.yml
+      - packaging/windows/**
+  schedule:
+    - cron: "41 4 * * 1" # weekly, so drift in the runner images shows up
+  workflow_dispatch:
+
+concurrency:
+  group: windows-arm64-${{ github.ref }}
+  cancel-in-progress: true
+
+permissions:
+  contents: read
+
+env:
+  CARGO_TERM_COLOR: always
+  CARGO_INCREMENTAL: 0
+
+jobs:
+  package:
+    name: package (cross-compiled on x64)
+    runs-on: windows-latest
+    timeout-minutes: 90
+    steps:
+      - uses: actions/checkout@v4
+      - uses: dtolnay/rust-toolchain@89b12181fb390509a0842a86cc55eeb8eb928c1d # stable
+        with:
+          targets: aarch64-pc-windows-msvc
+      - uses: Swatinem/rust-cache@6323deb102c322ba6fcbdcafc7e3dddab59af2b6 # v2
+        with:
+          key: windows-arm64-package
+      - name: Install WiX
+        shell: pwsh
+        run: dotnet tool install --global wix --version 5.0.2
+      - name: Build and package (unsigned)
+        shell: pwsh
+        env:
+          DIST: ${{ github.workspace }}\dist\arm64
+        run: ./packaging/windows/package.ps1 -Arch arm64
+      - uses: actions/upload-artifact@v4
+        with:
+          name: lightcraft-windows-arm64
+          path: dist/arm64/*
+          if-no-files-found: error
+          retention-days: 7
+
+  install:
+    name: install and run on ARM64
+    needs: package
+    runs-on: windows-11-arm
+    timeout-minutes: 30
+    steps:
+      - uses: actions/download-artifact@v4
+        with:
+          name: lightcraft-windows-arm64
+          path: dist
+      - name: Install the MSI, check it, run it, uninstall it
+        shell: pwsh
+        run: |
+          $ErrorActionPreference = 'Stop'
+          $msi = (Get-ChildItem dist/*.msi | Select-Object -First 1).FullName
+          $p = Start-Process msiexec.exe -ArgumentList '/i', "`"$msi`"", '/qn', '/l*v', 'install.log' -Wait -PassThru
+          if ($p.ExitCode -ne 0) { Get-Content install.log -Tail 60; throw "msiexec /i exited $($p.ExitCode)" }
+          $dir = Join-Path $env:ProgramFiles 'LightCraft'
+          foreach ($exe in 'lightcraft.exe', 'lightcraft-cli.exe') {
+            $path = Join-Path $dir $exe
+            if (-not (Test-Path $path)) { throw "$exe not installed in $dir" }
+            $bytes = [System.IO.File]::ReadAllBytes($path)
+            $machine = [BitConverter]::ToUInt16($bytes, [BitConverter]::ToInt32($bytes, 0x3C) + 4)
+            if ($machine -ne 0xAA64) { throw "$exe is for machine 0x$('{0:X}' -f $machine), not ARM64" }
+            Write-Output "ok $path (ARM64)"
+          }
+          # The installed CLI runs natively on ARM64.
+          $cli = Join-Path $dir 'lightcraft-cli.exe'
+          $out = & $cli --version 2>&1 | Out-String
+          if ($LASTEXITCODE -ne 0) { Write-Output $out; throw "lightcraft-cli --version exited $LASTEXITCODE" }
+          Write-Output "ok lightcraft-cli --version: $($out.Trim())"
+          $p = Start-Process msiexec.exe -ArgumentList '/x', "`"$msi`"", '/qn' -Wait -PassThru
+          if ($p.ExitCode -ne 0) { throw "msiexec /x exited $($p.ExitCode)" }
+          if (Test-Path (Join-Path $dir 'lightcraft.exe')) { throw 'uninstall left lightcraft.exe behind' }
+          Write-Output 'ok uninstalled'

.gitignore

@@ -7,3 +7,7 @@ plan/
 /log
 .DS_Store
 .claude/
+/craft-fonts
+# model weights are never committed (SAM 3: docs/ai-masks.md)
+*.safetensors
+*.safetensors.part

AGENTS.md

@@ -62,10 +62,21 @@ of it. Full standard: `../craftrules/standards/never-crash.md`
 ## Assets: icons, images, fonts (ABSOLUTE RULE — never violate)
 - **Never use any iconography, image, artwork, font, sound or other asset from Adobe products** (no Lightroom/Creative Cloud icons, no screenshots, no presets/profiles/LUTs, no UI bitmaps — not even as a temporary placeholder or "reference copy"). Observing Adobe's UI to imitate *layout and behaviour* is allowed; copying or tracing its assets is not.
 - **This includes Adobe's open-licensed assets**: no Source Sans/Serif/Code or Source Han fonts, no Adobe Fonts, no
-  Adobe-published icon sets, sample photos, colour profiles or LUTs — even when OFL/MIT. The UI font is Inter (OFL).
+  Adobe-published icon sets, sample photos, colour profiles or LUTs — even when OFL/MIT. The UI font is Inter (OFL);
+  Japanese fonts come from craft-fonts (below).
 - Every asset in the repository must be one of: **our own original work** (e.g. icons drawn in code as vectors, procedurally generated demo photos), **public domain / CC0**, **Creative Commons** (CC-BY / CC-BY-SA with attribution honoured), **OFL** (fonts), or **permissive open-source** (MIT/Apache-2.0/BSD/ISC) — or contributed by a person who created the asset and licenses it openly.
 - **Exception: `docs/brand/`.** The ArtCraft name, wordmark and logos there are ArtCraft Team trademarks, not open source and not covered by LightCraft's MIT OR Apache-2.0 licence (`LICENSE-MIT`, `LICENSE-APACHE`, `NOTICE`); their terms are in `docs/brand/LICENSE-brand.txt`. Use them only unmodified and never redraw, recolour or derive from them.
 - **Every asset must have an entry in `assets/ATTRIBUTION.md`** (path, title, author/creator, source URL or "original work", licence, date added, modifications) and its licence text when required (e.g. `assets/fonts/OFL-*.txt`). Add the entry in the same commit as the asset. Assets without an attribution entry must not be committed.
+- **Fonts live in [storytold/craft-fonts](https://github.com/storytold/craft-fonts), never in this repo.** Don't commit
+  font files here (Inter, already in `assets/fonts/`, is the one exception); add new fonts to craft-fonts. LightCraft
+  uses it as the optional build input `CRAFT_FONTS_DIR`: `git clone https://github.com/storytold/craft-fonts ../craft-fonts`
+  then `CRAFT_FONTS_DIR=../craft-fonts cargo run -p lightcraft` (or any cargo/xtask command). `crates/engine/build.rs`
+  embeds the manifest's fonts as `lightcraft_engine::CRAFT_FONTS` (wasm32: BIZ UDPGothic Regular only); the UI
+  (`theme::font_definitions`) and the export watermark renderer use its Japanese faces as fallbacks after Inter. Unset,
+  `CRAFT_FONTS` is empty: everything builds, tests and runs, but Japanese text has no glyphs. Releases always build
+  with it (`release.yml`, `CRAFT_FONTS_REQUIRED=1`) and ship the fonts' OFL licences. Tests that need these fonts skip
+  without it; the FreeBSD CI job runs them with it. Rules: craftrules
+  [`standards/fonts.md`](https://github.com/storytold/craftrules/blob/main/standards/fonts.md).
 - Icons drawn in code (e.g. `crates/ui-egui/src/icons.rs`) are original work and are recorded in `assets/ATTRIBUTION.md` as such; do not trace them from Adobe icons.
 - Demo/test images: generated procedurally by `lightcraft-scenes`, or CC0 downloads kept in the gitignored `corpus/` with their source recorded. Screenshots of Adobe apps live only in the gitignored `plan/` and are never committed or published.
 - **Enforced:** `cargo xtask assets` (in `ci`) fails when an image/icon/font/sound/video/raw/ICC/XMP file is not matched

CLAUDE.md

@@ -62,10 +62,21 @@ of it. Full standard: `../craftrules/standards/never-crash.md`
 ## Assets: icons, images, fonts (ABSOLUTE RULE — never violate)
 - **Never use any iconography, image, artwork, font, sound or other asset from Adobe products** (no Lightroom/Creative Cloud icons, no screenshots, no presets/profiles/LUTs, no UI bitmaps — not even as a temporary placeholder or "reference copy"). Observing Adobe's UI to imitate *layout and behaviour* is allowed; copying or tracing its assets is not.
 - **This includes Adobe's open-licensed assets**: no Source Sans/Serif/Code or Source Han fonts, no Adobe Fonts, no
-  Adobe-published icon sets, sample photos, colour profiles or LUTs — even when OFL/MIT. The UI font is Inter (OFL).
+  Adobe-published icon sets, sample photos, colour profiles or LUTs — even when OFL/MIT. The UI font is Inter (OFL);
+  Japanese fonts come from craft-fonts (below).
 - Every asset in the repository must be one of: **our own original work** (e.g. icons drawn in code as vectors, procedurally generated demo photos), **public domain / CC0**, **Creative Commons** (CC-BY / CC-BY-SA with attribution honoured), **OFL** (fonts), or **permissive open-source** (MIT/Apache-2.0/BSD/ISC) — or contributed by a person who created the asset and licenses it openly.
 - **Exception: `docs/brand/`.** The ArtCraft name, wordmark and logos there are ArtCraft Team trademarks, not open source and not covered by LightCraft's MIT OR Apache-2.0 licence (`LICENSE-MIT`, `LICENSE-APACHE`, `NOTICE`); their terms are in `docs/brand/LICENSE-brand.txt`. Use them only unmodified and never redraw, recolour or derive from them.
 - **Every asset must have an entry in `assets/ATTRIBUTION.md`** (path, title, author/creator, source URL or "original work", licence, date added, modifications) and its licence text when required (e.g. `assets/fonts/OFL-*.txt`). Add the entry in the same commit as the asset. Assets without an attribution entry must not be committed.
+- **Fonts live in [storytold/craft-fonts](https://github.com/storytold/craft-fonts), never in this repo.** Don't commit
+  font files here (Inter, already in `assets/fonts/`, is the one exception); add new fonts to craft-fonts. LightCraft
+  uses it as the optional build input `CRAFT_FONTS_DIR`: `git clone https://github.com/storytold/craft-fonts ../craft-fonts`
+  then `CRAFT_FONTS_DIR=../craft-fonts cargo run -p lightcraft` (or any cargo/xtask command). `crates/engine/build.rs`
+  embeds the manifest's fonts as `lightcraft_engine::CRAFT_FONTS` (wasm32: BIZ UDPGothic Regular only); the UI
+  (`theme::font_definitions`) and the export watermark renderer use its Japanese faces as fallbacks after Inter. Unset,
+  `CRAFT_FONTS` is empty: everything builds, tests and runs, but Japanese text has no glyphs. Releases always build
+  with it (`release.yml`, `CRAFT_FONTS_REQUIRED=1`) and ship the fonts' OFL licences. Tests that need these fonts skip
+  without it; the FreeBSD CI job runs them with it. Rules: craftrules
+  [`standards/fonts.md`](https://github.com/storytold/craftrules/blob/main/standards/fonts.md).
 - Icons drawn in code (e.g. `crates/ui-egui/src/icons.rs`) are original work and are recorded in `assets/ATTRIBUTION.md` as such; do not trace them from Adobe icons.
 - Demo/test images: generated procedurally by `lightcraft-scenes`, or CC0 downloads kept in the gitignored `corpus/` with their source recorded. Screenshots of Adobe apps live only in the gitignored `plan/` and are never committed or published.
 - **Enforced:** `cargo xtask assets` (in `ci`) fails when an image/icon/font/sound/video/raw/ICC/XMP file is not matched

Cargo.toml

@@ -3,7 +3,7 @@ resolver = "3"
 members = ["crates/*", "apps/*", "xtask"]
 
 [workspace.package]
-version = "0.2.0"
+version = "0.2.1"
 edition = "2024"
 license = "MIT OR Apache-2.0"
 rust-version = "1.90"
@@ -29,6 +29,7 @@ lightcraft-merge = { path = "crates/merge" }
 lightcraft-engine = { path = "crates/engine" }
 lightcraft-ui-egui = { path = "crates/ui-egui" }
 lightcraft-mcp = { path = "crates/mcp" }
+lightcraft-segment = { path = "crates/segment" }
 
 # foundation
 thiserror = "2"
@@ -62,6 +63,10 @@ jxl-oxide = { version = "0.12", default-features = false }
 ravif = { version = "0.13", default-features = false, features = ["threading"] } # no "asm": it needs nasm (non-Rust)
 
 # gpu (crates/gpu; native backends only, no GL: everything stays pure Rust)
+# SAM 3 inference (lightcraft-segment). 0.9.2: later releases pull `tokenizers` with the
+# Oniguruma C library into candle-core, and the product is pure Rust.
+candle-core = { version = "=0.9.2", default-features = false }
+candle-nn = { version = "=0.9.2", default-features = false }
 wgpu = { version = "30", default-features = false, features = ["std", "parking_lot", "metal", "vulkan", "dx12", "wgsl"] }
 pollster = "1"
 

NOTICE

@@ -15,6 +15,20 @@ list (author, source, license) is in assets/ATTRIBUTION.md.
 Inter (assets/fonts/Inter-*.ttf) — SIL Open Font License 1.1. See assets/fonts/OFL-Inter.txt.
 Showcase photographs by Ansel Adams, Dorothea Lange and NASA (docs/images/) — public domain. See assets/ATTRIBUTION.md.
 
-BIZ UDMincho: Copyright 2022 The BIZ UDMincho Project Authors
-(https://github.com/googlefonts/morisawa-biz-ud-mincho). SIL Open Font License 1.1;
-see assets/fonts/OFL-BIZUDMincho.txt.
+crates/segment (lightcraft-segment) ports the SAM 3 model code of Hugging Face Transformers
+(https://github.com/huggingface/transformers, src/transformers/models/sam3 and sam3_tracker),
+Copyright The HuggingFace Team and Meta Platforms, Inc., licensed under the Apache License 2.0.
+The port was modified by the LightCraft contributors (2026): translated from Python/PyTorch to
+Rust on candle and restructured; each ported file says so. Because of this, crates/segment is
+licensed under the Apache License 2.0 only (LICENSE-APACHE), not under the MIT option.
+
+The SAM 3 weights are not part of LightCraft and are never distributed with it. A user downloads
+the facebook/sam3 checkpoint only when they choose to (in the app, or by hand), under Meta's SAM
+License (https://github.com/facebookresearch/sam3/blob/main/LICENSE), a separate, non-OSI
+licence. See docs/ai-masks.md.
+
+Builds made with craft-fonts (the optional CRAFT_FONTS_DIR build input; all official releases)
+also embed the fonts listed in https://github.com/storytold/craft-fonts/blob/main/ATTRIBUTION.md
+(the Japanese fonts BIZ UDPGothic, BIZ UDMincho and Shippori Mincho; the web build embeds only BIZ
+UDPGothic Regular), under the SIL Open Font License 1.1. Release packages include each font's
+licence as OFL-<family>.txt.

README.md

@@ -334,6 +334,19 @@ cargo run --release -p lightcraft-cli -- render photo.jpg -o out.jpg --set light
 cargo xtask ci                                          # fmt, clippy, tests, layering, wasm checks
 ```
 
+**Chinese and Japanese text** need the shared font repo, an optional build input (official releases always include it):
+
+```sh
+git clone https://github.com/storytold/craft-fonts ../craft-fonts
+CRAFT_FONTS_DIR=../craft-fonts cargo run --release -p lightcraft
+```
+
+Without it LightCraft builds and runs the same, but Chinese and Japanese text have no glyphs. Fonts are never committed to this
+repo; see [craftrules `standards/fonts.md`](https://github.com/storytold/craftrules/blob/main/standards/fonts.md).
+
+**Interface language:** **Edit → Language** (English, 简体中文, 繁體中文（台灣）, 日本語) or **Settings → General →
+Language**; the choice applies immediately and persists. See [docs/localization.md](docs/localization.md).
+
 The web build needs the `wasm32-unknown-unknown` target and the matching `wasm-bindgen` CLI
 (`cargo xtask web` prints the exact install command); see [docs/web.md](docs/web.md).
 
@@ -356,7 +369,8 @@ Humans and agents follow the same rules, so read [AGENTS.md](AGENTS.md) first. T
   work from public specs and black-box observation.
 - **No Adobe assets, ever:** no icons, screenshots, presets, profiles, LUTs or fonts from Adobe products. Every
   image, icon and font in the repo is original, public domain, Creative Commons, OFL or permissively licensed, and has
-  an entry in [assets/ATTRIBUTION.md](assets/ATTRIBUTION.md) added in the same commit.
+  an entry in [assets/ATTRIBUTION.md](assets/ATTRIBUTION.md) added in the same commit. New fonts go to
+  [storytold/craft-fonts](https://github.com/storytold/craft-fonts), not here.
 - **Pure Rust**, enforced crate layering, everything is a command, and `cargo xtask ci` green before every commit
   (one task id per commit).
 - **Never crash.** Non-test code returns errors instead of panicking: no `unwrap()`, `expect()`, `panic!` or
@@ -420,7 +434,9 @@ with its author, source and license in [assets/ATTRIBUTION.md](assets/ATTRIBUTIO
 Showcase photographs are public-domain works, used via Wikimedia Commons: Ansel Adams, *The Tetons and the Snake River*
 (1942, U.S. National Archives); Dorothea Lange, *Migrant Mother* (1936, Library of Congress); Bill Anders / NASA,
 *Earthrise* (1968); NASA, *The Blue Marble* (1972). The demo library is procedurally generated by LightCraft. UI font:
-Inter (SIL OFL 1.1). All icons are original.
+Inter (SIL OFL 1.1). Builds made with [craft-fonts](https://github.com/storytold/craft-fonts) (all official releases)
+also embed its Chinese and Japanese fonts (Noto Sans CJK SC, BIZ UDPGothic, BIZ UDMincho, Shippori Mincho; SIL OFL 1.1), listed in its
+[ATTRIBUTION.md](https://github.com/storytold/craft-fonts/blob/main/ATTRIBUTION.md). All icons are original.
 
 The ArtCraft name, wordmark and logos in [`docs/brand/`](docs/brand/) are trademarks of the
 ArtCraft Team and are not covered by this license. They may be used only unmodified, and only as
@@ -433,3 +449,7 @@ Forks and modified versions must remove them.
   <a href="https://getartcraft.com/"><img alt="ArtCraft" src="docs/brand/artcraft-mark.svg" width="28"></a><br>
   <sub>Made by the <a href="https://getartcraft.com/">ArtCraft</a> team and community.</sub>
 </p>
+
+## Star history
+
+[![Star History Chart](https://api.star-history.com/svg?repos=storytold/lightcraft&type=Date&legend=top-left)](https://www.star-history.com/?repos=storytold%2Flightcraft&type=date&legend=top-left)

ROADMAP.md

@@ -23,30 +23,31 @@ duplicate Local entries #22, black GPU exports on an Intel iGPU #78).
 | Dimension | Estimate | What's true today | Biggest gaps |
 |---|---:|---|---|
 | **Feature checklist** | 79% | P0 core and P1 nearly complete: import (Add / Copy / Move, templates, devices), library, grid/loupe/compare/survey, every Edit slider, curves, colour grading, masking tools, crop/Upright, heal/clone, presets/profiles, versions/history, sync, export, menus, shortcuts | P1: lens-profile database, content-aware fill (patch synthesis), video playback/trim |
-| **RAW coverage** (formats people shoot) | ~50% | DNG (all kinds), CR2, ARW, NEF (uncompressed + Huffman lossless/lossy), uncompressed RAF/ORF, packed RW2, PEF; every container's embedded preview (incl. CR3) | **CR3** (every Canon since ~2018), compressed RAF/ORF, RW2 v4, Nikon lossy-after-split, Canon sRAW, HEIC/AVIF. Per-model verification is thin (~40 corpus files vs >1,000 models) |
-| **Colour & image quality** | ~55–65% | Pipeline is complete and fast; GPU path CPU-exact within 1/255 | **No camera colour calibration**: non-DNG raws use a neutral matrix, so colour is muted/inaccurate. No lens-profile database. No measured fidelity against Lightroom (tone, highlights, texture/clarity, NR, sharpening are tuned by eye) |
+| **RAW coverage** (formats people shoot) | ~50% | DNG (all kinds), CR2, ARW, NEF (uncompressed + Huffman lossless/lossy), uncompressed RAF/ORF, packed RW2, PEF; every container's embedded preview (incl. CR3) | **CR3** (every Canon since ~2018), compressed RAF/ORF, RW2 v4, Nikon lossy-after-split, Canon sRAW, HEIC/AVIF. NEFs labelled compressed but stored uncompressed (Z 6 packed 14-bit, D850 12-bit uncompressed). Per-model verification is thin (~40 corpus files vs >1,000 models) |
+| **Colour & image quality** | ~55–65% | Pipeline is complete and fast; GPU path CPU-exact within 1/255 | **No measured camera calibration database**: ARW and NEF have a guarded per-file embedded-JPEG colour estimate (docs/camera-preview-colour.md); other non-DNG raws and rejected estimates use a neutral matrix. Colour fidelity remains incomplete. No lens-profile database. No measured fidelity against Lightroom (tone, highlights, texture/clarity, NR, sharpening are tuned by eye) |
 | **AI & computational** | ~15–20% | Assisted culling (focus, bursts), auto tone, HDR/panorama merge; subject/sky/background masks as classical heuristics | Real segmentation masks (subject, sky, people, objects, landscape, depth), AI denoise, super resolution, lens blur, generative remove, faces/people, natural-language search. **Blocked on a model strategy** (licensable weights or our own training; pure-Rust inference is feasible) |
 | **Workflow & library** | ~85% (single machine) | Robust catalog (journal + snapshots, background compaction, crash-tested), 85k-photo libraries stay responsive, Local browsing with automatic cleanup, XMP interop, keywords, smart albums, Move import | Opening an 85k library takes 1.7–4.7 s; no cloud sync (out of scope), no tablet companion (#74, roadmap), shared albums, publish services, tethering |
 | **Classic modules** | ~30% | Geotagging from GPX track logs, soft proofing (partial), slideshow (basic) | **Map view, Book, Print, Slideshow module, Web, publish services**: ~40 tracker rows ⬜ |
 | **HDR & video** | 0% | | HDR edit/display/export; video play/trim/edit/export |
-| **Platform & robustness** | ~70% | macOS native; Windows/Linux builds; web via WASM; no-panic lints workspace-wide, `unsafe` confined to `crates/sysmem`; failed saves are reported; GPU errors fall back to CPU | Windows installer UI unverified on Windows (PR #79); GPU path proven only on Apple + user reports; no localisation; accessibility partial; headless UI tests time out under machine load |
+| **Platform & robustness** | ~70% | macOS native; Windows/Linux builds; web via WASM; no-panic lints workspace-wide, `unsafe` confined to `crates/sysmem`; failed saves are reported; GPU errors fall back to CPU | Windows installer UI unverified on Windows (PR #79); GPU path proven only on Apple + user reports; English, Simplified/Traditional Chinese and Japanese UI (see docs/localization.md); remaining technical errors; Traditional Chinese uses the Simplified Chinese font until craft-fonts has a TC face; accessibility partial; headless UI tests time out under machine load |
 
 ### By kind of user
 
 | User | Readiness | What blocks them |
 |---|---:|---|
 | JPEG / DNG shooter, single machine | ~85% | Fidelity polish, AI masks |
-| Nikon / Sony / older-Canon raw shooter | ~65% | Camera colour (muted colour on every photo) |
-| Canon CR3 / Fujifilm / Olympus shooter | ~35% | Their raws open as embedded previews only |
+| Nikon / Sony / older-Canon raw shooter | ~65% | Camera colour fidelity and coverage (ARW and NEF preview estimates are only a starting point) |
+| Canon CR3 / Fujifilm / Olympus shooter | ~35% | Their raws open as embedded previews only (CR3: the full-size JPEG with full metadata) |
 | Lightroom Classic power user | ~45% | Print, Book, Map, publish, tethering |
-| Relies on AI (masks, denoise) | ~25% | No segmentation or AI denoise models |
+| Relies on AI (masks, denoise) | ~25% | Object / Describe masks via optional SAM 3 (download not yet hosted); no AI denoise |
 
 ## Where we're going
 
 Priorities, in order. Each points at tracker rows in [`docs/parity.md`](docs/parity.md) → *Top gaps*.
 
 1. **Camera colour calibration of our own** (LR-PROF-CAMERACOLOR, P0): fit each camera to its own embedded JPEG, use
-   matrices the files carry themselves, then chart shots. Raises colour quality for every non-DNG raw at once.
+   matrices the files carry themselves, then chart shots. Sony ARW and Nikon NEF have the file-local fit (matrix + tone
+   curve from their own JPEG); generalise it to the other makes' raws (RW2, PEF, ORF…), then validate fidelity.
 2. **Raw formats, clean-room** (LR-IMP-FORMATS, P0): **CR3** first, then compressed RAF / ORF, RW2 v4, NEF
    lossy-after-split, sRAW. Decided 2026-10-05: write our own decoders from prose descriptions (never decoder source,
    no LGPL dependency); compressed NEF (#86) is the template.
@@ -56,7 +57,9 @@ Priorities, in order. Each points at tracker rows in [`docs/parity.md`](docs/par
    (references stay in the local `plan/`), then tune against the numbers.
 5. **Lens profiles of our own** (LR-EDIT-OPTICS-PROFILE, P1).
 6. **AI model strategy** (maintainer decision): which permissively licensed models (or our own training) for
-   segmentation masks and denoise; then pure-Rust inference. Unblocks M12 and Enhance.
+   segmentation masks and denoise; then pure-Rust inference. Unblocks M12 and Enhance. Object / Describe masks now
+   run Meta's SAM 3 in pure Rust (optional, user-consented download under the non-OSI SAM License; CDN mirrors still
+   to be set up, docs/ai-masks.md); Subject / Sky / People and Enhance are still open.
 7. **Then:** HDR (Q), the Classic output modules (Print first, then Map view, Book, Slideshow), video (R), localisation
    and accessibility.
 
@@ -81,12 +84,12 @@ hardening (#78), copyright metadata (#51), GPX geotagging (#60), import tag help
 | M8 | Heal / Remove | content-aware remove (PatchMatch), heal, clone, brush spots, visualize spots, red/pet eye | 6–10 | 🚧 (heal, clone, auto source, visualize spots, red/pet eye ✅; PatchMatch remove ⬜) |
 | M9 | Presets, profiles, versions, sync | preset browser + amount, create/import presets, profile browser, versions, history, copy/paste/sync settings | 5–8 | ✅ |
 | M10 | Export & share | export dialog (JPEG/PNG/TIFF/DNG/AVIF/JXL/original), sizing, sharpening, metadata, watermark, naming, batch jobs, XMP sidecars, HDR export | 6–10 | 🚧 (all formats incl. DNG/original, sizing, presets, background jobs ✅; JXL encode, HDR export ⬜) |
-| M11 | RAW II | CR3, RAF (X-Trans), ORF, RW2, PEF, SRW, 3FR, IIQ + long tail; camera calibration DB; HEIC/AVIF/JXL import | 20–35 | 🚧 (RAF uncompressed, RW2 packed, PEF, ORF uncompressed ✅; **camera colour calibration** ⬜ (top priority), CR3, compressed ORF/RAF ⬜) |
+| M11 | RAW II | CR3, RAF (X-Trans), ORF, RW2, PEF, SRW, 3FR, IIQ + long tail; camera calibration DB; HEIC/AVIF/JXL import | 20–35 | 🚧 (RAF uncompressed, RW2 packed, PEF, ORF uncompressed ✅; **camera colour calibration** 🚧 (guarded ARW and NEF preview fitting; measured database still missing), CR3, compressed ORF/RAF ⬜) |
 | M12 | AI & smart features | subject/sky/background/people/object masks, semantic search, faces/People (permissively licensed models, pure-Rust inference) | 20–40 | ⬜ |
 | M13 | Merge | HDR merge (deghost), panorama (projections, boundary warp, fill edges), HDR panorama | 10–15 | ✅ |
 | M14 | Video | import/playback/trim via FilmCraft crates, global edits + presets on video, video export | 6–10 | ⬜ |
 | M15 | Classic modules | Map, Book, Slideshow, Print, Web; smart collections, stacks, virtual copies, publish services, tethering | 25–40 | 🚧 (smart albums, stacks, virtual copies, compare/survey ✅; Map/Book/Slideshow/Print/Web ⬜) |
-| M16 | 1.0 polish | preferences, shortcut editor, accessibility, localization, packaging (dmg/msi/AppImage/web), hardening | 10–20 | 🚧 (settings, keyboard shortcuts sheet, packaging basics ✅; accessibility, localisation ⬜) |
+| M16 | 1.0 polish | preferences, shortcut editor, accessibility, localization, packaging (dmg/msi/AppImage/web), hardening | 10–20 | 🚧 (settings, keyboard shortcuts sheet, packaging basics ✅; English/Chinese (Simplified, Traditional)/Japanese localisation 🟡; accessibility and further locales ⬜) |
 
 ## Parity estimate (feature count updated 2026-10-05; effort estimate from 2026-10-02)
 
@@ -160,7 +163,8 @@ The milestone estimates in the table above were made before work started and are
 ## Raw format coverage and known gaps
 
 Decoded (CC0 corpus from raw.pixls.us, `cargo xtask corpus --download`, `crates/raw/tests/corpus.rs`): DNG (uncompressed,
-LJ92, lossy JPEG / Smart Previews, Deflate, float, linear), CR2, ARW (uncompressed, ARW2, LJ92), NEF/NRW uncompressed and Huffman-compressed (lossless, lossy type 1/2, 12/14-bit), RAF uncompressed (Bayer and
+LJ92, lossy JPEG / Smart Previews, Deflate, float, linear), CR2, ARW (uncompressed, ARW2, LJ92; as-shot white balance and black level of pre-2017 bodies from the enciphered
+maker-note `Tag2010` and the encrypted `SR2SubIFD`, both recovered by black-box analysis, `crates/raw/src/vendor/arw.rs`), NEF/NRW uncompressed and Huffman-compressed (lossless, lossy type 1/2, 12/14-bit), RAF uncompressed (Bayer and
 X-Trans), RW2 packed 12/14-bit, PEF (uncompressed and Huffman), ORF uncompressed (16-bit and 12-bit packed). Every
 supported container also yields its embedded JPEG preview (CR3 too), and the engine shows that preview for raw variants
 it can't decode yet.
@@ -175,7 +179,7 @@ Not decoded yet — preview only (no permissively licensed description; black-bo
   from the same-colour pixel two to the left), the reconstruction rule for scales 2/3 is not established.
 - **Olympus compressed ORF**, **Fujifilm compressed RAF**, **Canon CR3/CRX** (M11.1), **Canon sRAW/mRAW**, lossy DNG.
 
-**Camera colour matrices:** non-DNG raws use the documented neutral fallback (camera RGB ≈ linear sRGB, flagged
+**Camera colour matrices:** ARW files can use guarded, separate chromaticity and tone estimates from their own embedded JPEG (see `docs/camera-preview-colour.md`); this is a per-file camera-look estimate with relative WB, not measured calibration or absolute-Kelvin WB. Other non-DNG raws and rejected fits use the documented neutral fallback (camera RGB ≈ linear sRGB, flagged
 `matrix_is_fallback`) with the file's as-shot white-balance multipliers. Clean sources to evaluate next: manufacturer
 matrices stored in the files themselves (Olympus ImageProcessing `ColorMatrix`, Pentax/Panasonic equivalents) and our
 own chart-based calibration (M11.4). Adobe matrices are never used.
@@ -190,11 +194,14 @@ own chart-based calibration (M11.4). Adobe matrices are never used.
   export hardening, clippy 1.99. Added the honest *Where we stand* assessment and *Where we're going* priorities; added
   tracker rows for camera colour, camera coverage and render fidelity.
 
-## Japanese interface and text watermarks
+## Chinese and Japanese interfaces, and text watermarks
 
-English/Japanese interface language is persisted in UI state. Core menus have Japanese
-translations; untranslated panels and dialogs retain English. BIZ UDMincho is bundled
-under OFL for Japanese glyph coverage without system fonts. Text watermarks now accept
+English, Simplified Chinese, Traditional Chinese (Taiwan) and Japanese interface languages are persisted in UI state, and the
+language table (`crates/ui-egui/src/i18n.rs`) drives the menus, settings and fonts, so another
+language is a table entry plus two catalogs (docs/localization.md). Core menus and panels are
+translated; untranslated text retains English. CJK glyphs (Chinese: Noto Sans CJK SC; Japanese UI:
+BIZ UDPGothic; watermarks: BIZ UDMincho) come from storytold/craft-fonts, embedded by builds made
+with the optional `CRAFT_FONTS_DIR` input (all releases), so no system fonts are needed. Text watermarks now accept
 `vertical: true` in export JSON/presets and expose an orientation selector. Japanese
 characters stay upright in top-to-bottom columns, with newlines starting columns to the
 left. This is basic lettering, without tate-chu-yoko, ruby, kinsoku, or general vertical

apps/lightcraft-cli/src/main.rs

@@ -9,6 +9,7 @@
 //! lightcraft-cli synth-merge hdr|panorama -o DIR
 //! lightcraft-cli commands [--json]
 //! lightcraft-cli controls [--json]
+//! lightcraft-cli calibrate [--max N] [--out DIR] FOLDERS/FILES…
 //! ```
 #![forbid(unsafe_code)]
 #![deny(clippy::unwrap_used, clippy::expect_used, clippy::panic, clippy::unimplemented, clippy::todo, clippy::unreachable)]
@@ -84,6 +85,12 @@ USAGE:
       Write synthetic merge inputs (procedural scene; bracketed DNGs or overlapping PNG views).
   lightcraft-cli commands [--json]   list every command id with its parameters
   lightcraft-cli controls [--json]   list every develop control id with its range
+  lightcraft-cli calibrate [--max N] [--out DIR] FOLDERS/FILES…
+      Fit a colour profile per camera model from raw files and their embedded camera JPEGs
+      (Sony ARW, Nikon NEF): up to N files spread over the folders (default 300; 0 = all), pooled per
+      model, written as <model>.json to DIR (default: the profiles folder LightCraft reads,
+      <config>/camera-profiles, or $LIGHTCRAFT_CAMERA_PROFILES). Raws of a profiled model then
+      take their colour from the profile and only their tone from their own JPEG.
   lightcraft-cli --version | --help
 ";
 
@@ -125,6 +132,7 @@ fn main() -> ExitCode {
         Some("merge") => merge(&args[1..]),
         Some("synth-merge") => synth_merge(&args[1..]),
         Some("controls") => controls(&args[1..]),
+        Some("calibrate") => calibrate(&args[1..]),
         Some("--version" | "-V" | "version") => {
             println!("lightcraft-cli {}", env!("CARGO_PKG_VERSION"));
             Ok(())
@@ -144,6 +152,114 @@ fn main() -> ExitCode {
     }
 }
 
+/// Raw files below `path` (or `path` itself), skipping hidden and NAS metadata folders.
+fn raw_files(path: &Path, out: &mut Vec<std::path::PathBuf>, depth: usize) {
+    let is_raw = |p: &Path| p.extension().and_then(|e| e.to_str()).is_some_and(|e| ["arw", "nef", "nrw"].iter().any(|x| e.eq_ignore_ascii_case(x)));
+    if path.is_file() {
+        if is_raw(path) {
+            out.push(path.to_path_buf());
+        }
+        return;
+    }
+    let Ok(entries) = std::fs::read_dir(path) else { return };
+    if depth > 32 {
+        return;
+    }
+    for entry in entries.flatten() {
+        let name = entry.file_name();
+        if name.to_string_lossy().starts_with(['.', '@']) {
+            continue;
+        }
+        raw_files(&entry.path(), out, depth + 1);
+    }
+}
+
+fn calibrate(args: &[String]) -> Result<(), String> {
+    let mut max = 300usize;
+    let mut out: Option<std::path::PathBuf> = None;
+    let mut inputs = Vec::new();
+    let mut i = 0;
+    while i < args.len() {
+        match args[i].as_str() {
+            "--max" => max = take_value(args, &mut i, "--max")?.parse().map_err(|_| "--max needs a number".to_string())?,
+            "--out" => out = Some(take_value(args, &mut i, "--out")?.into()),
+            a if a.starts_with("--") => return Err(format!("unknown option `{a}`")),
+            f => inputs.push(f.to_string()),
+        }
+        i += 1;
+    }
+    if inputs.is_empty() {
+        return Err("calibrate needs folders or raw files".into());
+    }
+    let mut files = Vec::new();
+    for input in &inputs {
+        raw_files(Path::new(input), &mut files, 0);
+    }
+    files.sort();
+    files.dedup();
+    let found = files.len();
+    if max > 0 && files.len() > max {
+        // spread over all folders (dates, scenes) rather than the first N
+        files = (0..max).filter_map(|k| files.get(k * found / max).cloned()).collect();
+    }
+    eprintln!("calibrate: {} of {found} raw files", files.len());
+    let dir = out.or_else(lightcraft_engine::camera_profiles::dir).ok_or("no profiles folder: pass --out DIR")?;
+    let workers = std::thread::available_parallelism().map_or(4, |n| n.get()).clamp(1, 6);
+    let next = std::sync::atomic::AtomicUsize::new(0);
+    let done = std::sync::atomic::AtomicUsize::new(0);
+    let pools: Vec<lightcraft_engine::camera_profiles::Pool> = std::thread::scope(|scope| {
+        let handles: Vec<_> = (0..workers)
+            .map(|_| {
+                scope.spawn(|| {
+                    let mut pool = lightcraft_engine::camera_profiles::Pool::default();
+                    while let Some(path) = files.get(next.fetch_add(1, std::sync::atomic::Ordering::Relaxed)) {
+                        let result = std::fs::read(path).map_err(|e| e.to_string()).and_then(|bytes| pool.add(&bytes));
+                        let n = done.fetch_add(1, std::sync::atomic::Ordering::Relaxed) + 1;
+                        match result {
+                            Ok(Some(model)) => eprintln!("[{n}/{}] {} ({model})", files.len(), path.display()),
+                            Ok(None) => eprintln!("[{n}/{}] {}: skipped (no usable camera JPEG or colour)", files.len(), path.display()),
+                            Err(e) => eprintln!("[{n}/{}] {}: {e}", files.len(), path.display()),
+                        }
+                    }
+                    pool
+                })
+            })
+            .collect();
+        handles.into_iter().filter_map(|h| h.join().ok()).collect()
+    });
+    let mut pool = lightcraft_engine::camera_profiles::Pool::default();
+    for p in pools {
+        pool.merge(p);
+    }
+    let mut written = 0;
+    for result in pool.fit(5) {
+        match result {
+            Ok(profile) => {
+                let path = lightcraft_engine::camera_profiles::save(&profile, &dir)?;
+                println!(
+                    "{}: {} photos, {} colour pairs, hue/saturation table {} → {}",
+                    profile.model,
+                    profile.files,
+                    profile.samples,
+                    profile.hue_sat.is_some(),
+                    path.display()
+                );
+                written += 1;
+            }
+            Err(e) => eprintln!("calibrate: {e}"),
+        }
+    }
+    for (model, n) in pool.files() {
+        if n < 5 {
+            eprintln!("calibrate: {model}: only {n} usable photo(s), at least 5 needed");
+        }
+    }
+    if written == 0 {
+        return Err("no profile written".into());
+    }
+    Ok(())
+}
+
 fn mcp(args: &[String]) -> Result<(), String> {
     let mut connect: Option<String> = None;
     let mut demo = false;
@@ -416,39 +532,39 @@ fn run(args: &[String]) -> Result<(), String> {
     if steps.is_empty() {
         return Err("run: no command given (see `lightcraft-cli commands`)".into());
     }
-    let mut backend: Box<dyn Backend> = match connect {
-        Some(addr) => {
-            if demo || library.is_some() || !imports.is_empty() {
-                return Err("--demo, --library and --import apply to headless mode only".into());
-            }
-            Box::new(
-                Remote::connect(&addr)
-                    .map_err(|e| format!("LightCraft is not reachable at {addr} ({e}); start it with `lightcraft --control 7980`"))?,
-            )
-        }
-        None => {
-            let mut h = match &library {
-                Some(dir) => {
-                    let mut h = Headless::default();
-                    h.session.open_library(dir, demo).map_err(|e| library_error(dir, e))?;
-                    h
-                }
-                None if demo => Headless::demo(),
-                None => Headless::default(),
-            };
-            if !imports.is_empty() {
-                let paths = expand_paths(&imports);
-                let r = h.session.execute("library.import", &json!({"paths": paths})).map_err(|e| e.to_string())?;
-                // what follows acts on the imported photos (already-known files are reported as duplicates)
-                let mut ids: Vec<Value> = r["imported"].as_array().cloned().unwrap_or_default();
-                ids.extend(r["duplicates"].as_array().into_iter().flatten().filter_map(|d| d.get("existing").filter(|v| v.is_u64()).cloned()));
-                if let Some(first) = ids.first().cloned() {
-                    h.session.execute("library.select", &json!({"ids": ids, "active": first})).map_err(|e| e.to_string())?;
+    let mut backend: Box<dyn Backend> =
+        match connect {
+            Some(addr) => {
+                if demo || library.is_some() || !imports.is_empty() {
+                    return Err("--demo, --library and --import apply to headless mode only".into());
                 }
+                Box::new(Remote::connect(&addr).map_err(|e| {
+                    format!("LightCraft is not reachable at {addr} ({e}); start it with `lightcraft --control {}`", connect_port(&addr))
+                })?)
             }
-            Box::new(h)
-        }
-    };
+            None => {
+                let mut h = match &library {
+                    Some(dir) => {
+                        let mut h = Headless::default();
+                        h.session.open_library(dir, demo).map_err(|e| library_error(dir, e))?;
+                        h
+                    }
+                    None if demo => Headless::demo(),
+                    None => Headless::default(),
+                };
+                if !imports.is_empty() {
+                    let paths = expand_paths(&imports);
+                    let r = h.session.execute("library.import", &json!({"paths": paths})).map_err(|e| e.to_string())?;
+                    // what follows acts on the imported photos (already-known files are reported as duplicates)
+                    let mut ids: Vec<Value> = r["imported"].as_array().cloned().unwrap_or_default();
+                    ids.extend(r["duplicates"].as_array().into_iter().flatten().filter_map(|d| d.get("existing").filter(|v| v.is_u64()).cloned()));
+                    if let Some(first) = ids.first().cloned() {
+                        h.session.execute("library.select", &json!({"ids": ids, "active": first})).map_err(|e| e.to_string())?;
+                    }
+                }
+                Box::new(h)
+            }
+        };
     let mut out = std::io::stdout().lock();
     let mut failed = 0;
     for s in &steps {
@@ -474,6 +590,12 @@ fn take_value<'a>(args: &'a [String], i: &mut usize, flag: &str) -> Result<&'a s
     args.get(*i).map(String::as_str).ok_or_else(|| format!("{flag} needs a value"))
 }
 
+/// The port an `--connect` address names, for the recovery hint. The whole address when it has
+/// no port, so a hint is never built from a guess.
+fn connect_port(addr: &str) -> &str {
+    addr.rsplit_once(':').map_or(addr, |(_, port)| port)
+}
+
 fn render(args: &[String]) -> Result<(), String> {
     let mut input = None;
     let mut output = None;

apps/lightcraft-cli/tests/cli.rs

@@ -183,6 +183,42 @@ fn snapshot_subcommand_renders_the_ui_headlessly() {
     assert_eq!((d.width, d.height), (640, 480));
 }
 
+/// Issue #136: with the GPU switched off from the environment the UI starts and renders on the CPU,
+/// without creating a GPU device (no driver is loaded), and says why.
+#[test]
+fn snapshot_starts_without_a_gpu() {
+    let script = tmp("nogpu.jsonl");
+    std::fs::write(
+        &script,
+        format!(
+            "{}\n{}\n{}\n",
+            json!({"method": "ui.set", "params": {"view": "photoGrid"}}),
+            json!({"method": "engine.execute", "params": {"command": "app.gpu"}}),
+            json!({"method": "ui.screenshot"}),
+        ),
+    )
+    .unwrap();
+    for (var, value, reason) in [("LIGHTCRAFT_GPU", "0", "LIGHTCRAFT_GPU=0"), ("LIGHTCRAFT_GPU_BACKEND", "off", "LIGHTCRAFT_GPU_BACKEND=off")] {
+        let out = tmp(&format!("nogpu-{var}.png"));
+        let o = Command::new(BIN)
+            .env_remove("LIGHTCRAFT_GPU")
+            .env_remove("LIGHTCRAFT_GPU_BACKEND")
+            .env(var, value)
+            .args(["snapshot", "--demo", "--script", script.to_str().unwrap(), "-o", out.to_str().unwrap(), "--size", "480x320"])
+            .output()
+            .unwrap();
+        assert!(o.status.success(), "{var}: {}", String::from_utf8_lossy(&o.stderr));
+        let replies: Vec<Value> = String::from_utf8_lossy(&o.stdout).lines().map(|l| serde_json::from_str(l).unwrap()).collect();
+        assert!(replies.iter().all(|r| r["ok"] == true), "{replies:?}");
+        let gpu = &replies[1]["result"];
+        assert_eq!(gpu["available"], false, "{var}: {gpu}");
+        assert_eq!(gpu["adapter"], Value::Null, "{var}: no device was created: {gpu}");
+        assert!(gpu["reason"].as_str().is_some_and(|r| r.contains(reason)), "{var}: {gpu}");
+        let d = lightcraft_codecs::decode(&std::fs::read(&out).unwrap(), Default::default()).unwrap();
+        assert_eq!((d.width, d.height), (480, 320));
+    }
+}
+
 fn run_cli(args: &[&str], stdin: Option<&str>) -> (bool, Vec<Value>, String) {
     let mut child = Command::new(BIN).arg("run").args(args).stdin(Stdio::piped()).stdout(Stdio::piped()).stderr(Stdio::piped()).spawn().unwrap();
     if let Some(text) = stdin {
@@ -288,3 +324,13 @@ fn a_library_open_in_another_process_is_refused() {
     assert_eq!(lines[0]["ok"], true);
     let _ = std::fs::remove_dir_all(&lib);
 }
+
+/// Issue #167: when `--connect ADDR` cannot reach the app, the recovery hint must name the port
+/// ADDR actually names — following the old fixed "7980" left the retry connecting elsewhere.
+#[test]
+fn connect_failure_hint_names_the_attempted_port() {
+    let (ok, _lines, err) = run_cli(&["--connect", "127.0.0.1:18437", "ui.inspect"], None);
+    assert!(!ok);
+    assert!(err.contains("--control 18437"), "the hint must name the port it tried: {err}");
+    assert!(!err.contains("--control 7980"), "{err}");
+}

apps/lightcraft-web/Cargo.toml

@@ -21,6 +21,7 @@ lightcraft-preview = { workspace = true }
 serde = { workspace = true }
 serde_json = { workspace = true }
 log = { workspace = true }
+crc32fast = { workspace = true }
 
 [target.'cfg(target_arch = "wasm32")'.dependencies]
 eframe = { workspace = true, features = ["default_fonts", "glow"] }

apps/lightcraft-web/src/backend.rs

@@ -232,6 +232,18 @@ impl Backend {
         }
     }
 
+    /// Is there a file at `path`?
+    pub async fn exists(&self, path: &str) -> Result<bool, String> {
+        match self {
+            Backend::Opfs(root) => Ok(Self::opfs_file(root, path, false).await?.is_some()),
+            Backend::Idb(db) => {
+                let (_tx, store) = Self::idb_store(db, false)?;
+                let n = idb_req(&store.count_with_key(&path.into()).map_err(err)?).await?;
+                Ok(n.as_f64().is_some_and(|n| n > 0.0))
+            }
+        }
+    }
+
     pub async fn remove(&self, path: &str) -> Result<(), String> {
         match self {
             Backend::Opfs(root) => {
@@ -309,14 +321,25 @@ async fn dir_keys(dir: &FileSystemDirectoryHandle) -> Result<Vec<String>, String
     Ok(out)
 }
 
-/// Ask the browser not to evict our storage under pressure (best effort; fire and forget).
-pub fn request_persistence() {
-    if let Some(sm) = storage_manager()
-        && let Ok(p) = sm.persist()
-    {
-        wasm_bindgen_futures::spawn_local(async move {
-            let granted = JsFuture::from(p).await.ok().is_some_and(|v| v.is_truthy());
-            log::info!("lightcraft: persistent storage {}", if granted { "granted" } else { "not granted (best effort)" });
-        });
-    }
+/// Ask the browser not to evict our storage under pressure; `on_result(granted)` once known
+/// (`false` also when the browser has no storage manager).
+pub fn request_persistence(on_result: impl FnOnce(bool) + 'static) {
+    let Some(sm) = storage_manager() else {
+        on_result(false);
+        return;
+    };
+    wasm_bindgen_futures::spawn_local(async move {
+        // already persistent: nothing to ask
+        let already = match sm.persisted() {
+            Ok(p) => JsFuture::from(p).await.ok().is_some_and(|v| v.is_truthy()),
+            Err(_) => false,
+        };
+        let granted = already
+            || match sm.persist() {
+                Ok(p) => JsFuture::from(p).await.ok().is_some_and(|v| v.is_truthy()),
+                Err(_) => false,
+            };
+        log::info!("lightcraft: persistent storage {}", if granted { "granted" } else { "not granted" });
+        on_result(granted);
+    });
 }

apps/lightcraft-web/src/backup.rs

@@ -0,0 +1,306 @@
+//! Library backups for the browser build: a plain zip (entries stored, not compressed — photos
+//! don't shrink) of the library files and every stored original, built one entry at a time so
+//! only one file is in wasm memory at once, and read back the same way for a restore.
+//!
+//! Layout of a backup:
+//! - `library/catalog.snap`, `library/catalog.log`, `library/presets.json`, … (see
+//!   [`crate::files::LIBRARY_FILES`]);
+//! - `originals/<content hash>/<file name>`: each imported photo's original bytes, under its own
+//!   name so an unzipped backup is browsable;
+//! - `README.txt`.
+//!
+//! Restoring never deletes anything: the library files go to a new library folder in browser
+//! storage, originals that aren't stored yet are added (they're named by content, so existing
+//! ones are identical), and only then does a small pointer file ([`ACTIVE_LIBRARY`]) switch to
+//! the restored library. The library that was there before stays in storage.
+//!
+//! No zip64: a backup holds at most [`MAX_BYTES`] and 65 535 entries.
+
+/// Storage key of the file naming the library folder in use (absent: `library`).
+pub const ACTIVE_LIBRARY: &str = "active-library";
+
+/// The default library folder.
+pub const DEFAULT_LIBRARY_DIR: &str = "library";
+
+/// Largest backup (offsets are 32-bit without zip64).
+pub const MAX_BYTES: u64 = 0xFFFF_FFFF - (64 << 20);
+
+const LOCAL_SIG: u32 = 0x0403_4b50;
+const CENTRAL_SIG: u32 = 0x0201_4b50;
+const END_SIG: u32 = 0x0605_4b50;
+/// General-purpose flag bit 11: names are UTF-8.
+const UTF8: u16 = 0x0800;
+/// 1980-01-01 00:00 in MS-DOS format (date, time).
+const DOS_DATE: u16 = (1 << 5) | 1;
+
+/// The readme inside every backup.
+pub const README: &str = "LightCraft library backup (browser version)\n\n\
+library/      the catalog (catalog.snap + catalog.log), presets, view state and preferences\n\
+originals/    every imported photo, as originals/<content hash>/<file name>\n\n\
+Restore it in LightCraft for the web with File > Restore Library from Backup...\n\
+The photos in originals/ are the untouched files you imported; edits live in the catalog.\n";
+
+/// Is `name` a safe library folder name (`library` or `library-<letters, digits, ->`)?
+pub fn valid_library_dir(name: &str) -> bool {
+    name == DEFAULT_LIBRARY_DIR
+        || name.strip_prefix("library-").is_some_and(|s| !s.is_empty() && s.len() <= 64 && s.chars().all(|c| c.is_ascii_alphanumeric() || c == '-'))
+}
+
+/// Is `h` a plausible content hash (used as a storage key segment)?
+pub fn valid_hash(h: &str) -> bool {
+    !h.is_empty() && h.len() <= 128 && h.chars().all(|c| c.is_ascii_alphanumeric())
+}
+
+/// Zip entry name for an original.
+pub fn original_entry(hash: &str, file_name: &str) -> String {
+    let name: String = file_name.chars().map(|c| if c == '/' || c == '\\' || c.is_control() { '_' } else { c }).collect();
+    let name = if name.is_empty() || name == "." || name == ".." { "original".to_string() } else { name };
+    format!("originals/{hash}/{name}")
+}
+
+/// Where a backup entry goes when restoring into library folder `dir`: `Some(storage key)`, or
+/// `None` to skip it (README, thumbnails, anything unknown or unsafe).
+pub fn restore_key(entry: &str, dir: &str) -> Option<String> {
+    if let Some(name) = entry.strip_prefix("library/") {
+        return crate::files::LIBRARY_FILES.contains(&name).then(|| format!("{dir}/{name}"));
+    }
+    let rest = entry.strip_prefix("originals/")?;
+    let (hash, _) = rest.split_once('/').unwrap_or((rest, ""));
+    valid_hash(hash).then(|| format!("originals/{hash}"))
+}
+
+fn u16le(v: &mut Vec<u8>, x: u16) {
+    v.extend_from_slice(&x.to_le_bytes());
+}
+fn u32le(v: &mut Vec<u8>, x: u32) {
+    v.extend_from_slice(&x.to_le_bytes());
+}
+
+struct Central {
+    name: String,
+    crc: u32,
+    size: u32,
+    offset: u32,
+}
+
+/// Writes a stored (uncompressed) zip piece by piece: [`ZipWriter::entry`] returns the local
+/// header to emit before the entry's bytes, [`ZipWriter::finish`] the central directory.
+#[derive(Default)]
+pub struct ZipWriter {
+    entries: Vec<Central>,
+    offset: u64,
+}
+
+impl ZipWriter {
+    /// The local header for `name` holding `data` (emit it, then `data`).
+    pub fn entry(&mut self, name: &str, data: &[u8]) -> Result<Vec<u8>, String> {
+        let size = u32::try_from(data.len()).map_err(|_| format!("{name}: larger than 4 GB"))?;
+        let name_len = u16::try_from(name.len()).map_err(|_| format!("{name}: name too long"))?;
+        if self.entries.len() >= usize::from(u16::MAX) {
+            return Err("too many files for one backup".into());
+        }
+        let header_len = 30 + u64::from(name_len);
+        if self.offset + header_len + u64::from(size) > MAX_BYTES {
+            return Err("the library is too large for one backup file (4 GB)".into());
+        }
+        let offset = u32::try_from(self.offset).map_err(|_| "backup too large".to_string())?;
+        let crc = crc32fast::hash(data);
+        let mut h = Vec::with_capacity(header_len as usize);
+        u32le(&mut h, LOCAL_SIG);
+        u16le(&mut h, 20); // version needed
+        u16le(&mut h, UTF8);
+        u16le(&mut h, 0); // stored
+        u16le(&mut h, 0); // time
+        u16le(&mut h, DOS_DATE);
+        u32le(&mut h, crc);
+        u32le(&mut h, size);
+        u32le(&mut h, size);
+        u16le(&mut h, name_len);
+        u16le(&mut h, 0); // extra
+        h.extend_from_slice(name.as_bytes());
+        self.offset += header_len + u64::from(size);
+        self.entries.push(Central { name: name.to_string(), crc, size, offset });
+        Ok(h)
+    }
+
+    /// The central directory and end record (emit last).
+    pub fn finish(self) -> Result<Vec<u8>, String> {
+        let mut cd = Vec::new();
+        for e in &self.entries {
+            u32le(&mut cd, CENTRAL_SIG);
+            u16le(&mut cd, 20); // made by
+            u16le(&mut cd, 20); // needed
+            u16le(&mut cd, UTF8);
+            u16le(&mut cd, 0);
+            u16le(&mut cd, 0);
+            u16le(&mut cd, DOS_DATE);
+            u32le(&mut cd, e.crc);
+            u32le(&mut cd, e.size);
+            u32le(&mut cd, e.size);
+            u16le(&mut cd, e.name.len() as u16);
+            u16le(&mut cd, 0); // extra
+            u16le(&mut cd, 0); // comment
+            u16le(&mut cd, 0); // disk
+            u16le(&mut cd, 0); // internal attrs
+            u32le(&mut cd, 0); // external attrs
+            u32le(&mut cd, e.offset);
+            cd.extend_from_slice(e.name.as_bytes());
+        }
+        let cd_offset = u32::try_from(self.offset).map_err(|_| "backup too large".to_string())?;
+        let cd_size = u32::try_from(cd.len()).map_err(|_| "backup too large".to_string())?;
+        let n = self.entries.len() as u16;
+        let mut out = cd;
+        u32le(&mut out, END_SIG);
+        u16le(&mut out, 0);
+        u16le(&mut out, 0);
+        u16le(&mut out, n);
+        u16le(&mut out, n);
+        u32le(&mut out, cd_size);
+        u32le(&mut out, cd_offset);
+        u16le(&mut out, 0); // comment
+        Ok(out)
+    }
+}
+
+/// One entry of a zip's central directory.
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub struct ZipEntry {
+    pub name: String,
+    pub crc: u32,
+    pub size: u64,
+    /// Offset of the entry's local header.
+    pub header: u64,
+    /// 0 = stored (the only method a restore reads).
+    pub method: u16,
+}
+
+fn rd16(b: &[u8], at: usize) -> Option<u16> {
+    Some(u16::from_le_bytes(b.get(at..at + 2)?.try_into().ok()?))
+}
+fn rd32(b: &[u8], at: usize) -> Option<u32> {
+    Some(u32::from_le_bytes(b.get(at..at + 4)?.try_into().ok()?))
+}
+
+/// How many bytes from the end of a zip to read to find its end record.
+pub fn tail_len(file_len: u64) -> u64 {
+    file_len.min(22 + 65_535)
+}
+
+/// The central directory's (offset, size) from the last [`tail_len`] bytes of a zip.
+pub fn find_central(tail: &[u8]) -> Result<(u64, u64), String> {
+    let at = (0..tail.len().saturating_sub(21)).rev().find(|&i| rd32(tail, i) == Some(END_SIG)).ok_or("not a zip file (no end record)")?;
+    let size = rd32(tail, at + 12).ok_or("truncated zip")?;
+    let offset = rd32(tail, at + 16).ok_or("truncated zip")?;
+    if size == u32::MAX || offset == u32::MAX {
+        return Err("zip64 backups are not supported".into());
+    }
+    Ok((u64::from(offset), u64::from(size)))
+}
+
+/// Parse a central directory.
+pub fn parse_central(cd: &[u8]) -> Result<Vec<ZipEntry>, String> {
+    let mut out = Vec::new();
+    let mut i = 0;
+    while i + 46 <= cd.len() {
+        if rd32(cd, i) != Some(CENTRAL_SIG) {
+            return Err("damaged zip directory".into());
+        }
+        let bad = || "damaged zip directory".to_string();
+        let method = rd16(cd, i + 10).ok_or_else(bad)?;
+        let crc = rd32(cd, i + 16).ok_or_else(bad)?;
+        let size = rd32(cd, i + 24).ok_or_else(bad)?;
+        let n = usize::from(rd16(cd, i + 28).ok_or_else(bad)?);
+        let extra = usize::from(rd16(cd, i + 30).ok_or_else(bad)?);
+        let comment = usize::from(rd16(cd, i + 32).ok_or_else(bad)?);
+        let header = rd32(cd, i + 42).ok_or_else(bad)?;
+        let name = cd.get(i + 46..i + 46 + n).ok_or_else(bad)?;
+        out.push(ZipEntry { name: String::from_utf8_lossy(name).into_owned(), crc, size: u64::from(size), header: u64::from(header), method });
+        i += 46 + n + extra + comment;
+    }
+    Ok(out)
+}
+
+/// Offset of an entry's data from its local header's first 30 bytes.
+pub fn data_offset(entry: &ZipEntry, local: &[u8]) -> Result<u64, String> {
+    if rd32(local, 0) != Some(LOCAL_SIG) {
+        return Err(format!("{}: damaged entry", entry.name));
+    }
+    let n = rd16(local, 26).ok_or("truncated entry")?;
+    let extra = rd16(local, 28).ok_or("truncated entry")?;
+    Ok(entry.header + 30 + u64::from(n) + u64::from(extra))
+}
+
+/// Check an entry's bytes.
+pub fn verify(entry: &ZipEntry, data: &[u8]) -> Result<(), String> {
+    if entry.method != 0 {
+        return Err(format!("{}: compressed entries are not supported (not a LightCraft backup?)", entry.name));
+    }
+    if data.len() as u64 != entry.size || crc32fast::hash(data) != entry.crc {
+        return Err(format!("{}: damaged (checksum mismatch)", entry.name));
+    }
+    Ok(())
+}
+
+/// A name for the restored library's folder.
+pub fn restored_dir_name(now_ms: f64) -> String {
+    format!("library-restored-{}", now_ms.max(0.0) as u64)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn build(files: &[(&str, &[u8])]) -> Vec<u8> {
+        let mut w = ZipWriter::default();
+        let mut out = Vec::new();
+        for (n, d) in files {
+            out.extend(w.entry(n, d).unwrap());
+            out.extend_from_slice(d);
+        }
+        out.extend(w.finish().unwrap());
+        out
+    }
+
+    #[test]
+    fn written_backups_read_back() {
+        let files: [(&str, &[u8]); 3] =
+            [("README.txt", README.as_bytes()), ("library/catalog.log", b"{\"seq\":1}\n"), ("originals/abc123/IMG 1.jpg", &[0, 1, 2, 3, 255])];
+        let zip = build(&files);
+        let tail = &zip[zip.len() - tail_len(zip.len() as u64) as usize..];
+        let (off, size) = find_central(tail).unwrap();
+        let entries = parse_central(&zip[off as usize..(off + size) as usize]).unwrap();
+        assert_eq!(entries.len(), 3);
+        for (e, (name, data)) in entries.iter().zip(files) {
+            assert_eq!(e.name, name);
+            let start = data_offset(e, &zip[e.header as usize..e.header as usize + 30]).unwrap() as usize;
+            let got = &zip[start..start + e.size as usize];
+            assert_eq!(got, data);
+            verify(e, got).unwrap();
+        }
+        // damage is caught
+        let e = &entries[2];
+        assert!(verify(e, &[0, 1, 2, 3, 254]).is_err());
+        assert!(find_central(b"not a zip at all, just some text").is_err());
+    }
+
+    #[test]
+    fn restore_keys_are_safe() {
+        assert_eq!(restore_key("library/catalog.snap", "library-restored-1").as_deref(), Some("library-restored-1/catalog.snap"));
+        assert_eq!(restore_key("library/../../x", "library-r"), None);
+        assert_eq!(restore_key("library/evil.bin", "library-r"), None);
+        assert_eq!(restore_key("originals/abc123/IMG.jpg", "d").as_deref(), Some("originals/abc123"));
+        assert_eq!(restore_key("originals/../library/catalog.log", "d"), None);
+        assert_eq!(restore_key("README.txt", "d"), None);
+        assert_eq!(restore_key("thumbs/x.jpg", "d"), None);
+        assert_eq!(original_entry("abc", "a/b\\c.jpg"), "originals/abc/a_b_c.jpg");
+        assert_eq!(original_entry("abc", ".."), "originals/abc/original");
+        assert!(valid_library_dir("library") && valid_library_dir("library-restored-17"));
+        assert!(!valid_library_dir("library-../x") && !valid_library_dir("originals") && !valid_library_dir("library-"));
+    }
+
+    #[test]
+    fn size_limits_are_errors_not_panics() {
+        let mut w = ZipWriter { offset: MAX_BYTES - 10, ..Default::default() };
+        assert!(w.entry("x", &[0; 64]).is_err());
+    }
+}

apps/lightcraft-web/src/files.rs

@@ -49,6 +49,8 @@ struct Mirror {
     files: BTreeMap<String, Vec<u8>>,
     /// Dirty files, least recently modified first.
     dirty: Vec<(String, Dirty)>,
+    /// Why the last flush to browser storage failed (quota, eviction…), until one succeeds.
+    error: Option<String>,
 }
 
 impl Mirror {
@@ -138,6 +140,18 @@ impl Files {
         }
     }
 
+    /// Record the outcome of a flush to browser storage: `Some(why)` when it failed, `None` once
+    /// one succeeds. While a flush is failing, the catalog [`Store`] refuses new writes, so the
+    /// engine keeps the changes queued and reports them unsaved (`library.info` → `unsavedOps`,
+    /// the top bar's warning) instead of pretending they were saved.
+    pub fn set_error(&self, e: Option<String>) {
+        self.lock().error = e;
+    }
+
+    pub fn error(&self) -> Option<String> {
+        self.lock().error.clone()
+    }
+
     /// A catalog [`Store`] over these files.
     pub fn store(&self) -> FilesStore {
         FilesStore(self.clone())
@@ -147,19 +161,32 @@ impl Files {
 /// [`Store`] implementation over [`Files`].
 pub struct FilesStore(Files);
 
+impl FilesStore {
+    /// Writes fail while browser storage does (see [`Files::set_error`]).
+    fn writable(&self) -> io::Result<()> {
+        match self.0.error() {
+            Some(e) => Err(io::Error::other(format!("browser storage: {e}"))),
+            None => Ok(()),
+        }
+    }
+}
+
 impl Store for FilesStore {
     fn read(&mut self, name: &str) -> io::Result<Option<Vec<u8>>> {
         Ok(self.0.get(name))
     }
     fn write_atomic(&mut self, name: &str, data: &[u8]) -> io::Result<()> {
+        self.writable()?;
         self.0.write(name, data);
         Ok(())
     }
     fn append(&mut self, name: &str, data: &[u8]) -> io::Result<()> {
+        self.writable()?;
         self.0.append(name, data);
         Ok(())
     }
     fn truncate(&mut self, name: &str, len: u64) -> io::Result<()> {
+        self.writable()?;
         self.0.truncate(name, len as usize);
         Ok(())
     }
@@ -224,6 +251,37 @@ mod tests {
         assert_eq!(names, ["catalog.snap", "catalog.log"]);
     }
 
+    /// A failing flush (quota exceeded, storage evicted) is not silent: commands report the change
+    /// as unsaved and the engine keeps it queued; once storage works again it is written.
+    #[test]
+    fn flush_failures_show_as_unsaved_and_are_retried() {
+        let mut disk = BTreeMap::new();
+        let files = Files::default();
+        let mut s = Session::new();
+        let stores = LibraryStores { dir: "browser".into(), catalog: Box::new(files.store()), files: Box::new(files.store()), on_disk: false };
+        s.open_library_in(stores, true).unwrap();
+        flush(&files, &mut disk);
+        files.set_error(Some("QuotaExceededError".into()));
+        let r = s.execute("photo.rate", &json!({"rating": 5}));
+        assert!(matches!(r, Err(lightcraft_engine::EngineError::NotSaved(_))), "{r:?}");
+        let (ops, why) = s.unsaved().unwrap();
+        assert!(ops > 0 && why.contains("QuotaExceeded"), "{why}");
+        files.set_error(None);
+        s.persist_if_dirty();
+        s.persist().unwrap();
+        assert!(s.unsaved().is_none(), "written once storage works again");
+        flush(&files, &mut disk);
+        let id = s.selection.active.unwrap();
+        let files2 = Files::default();
+        for (k, v) in &disk {
+            files2.preload(k, v.clone());
+        }
+        let mut s2 = Session::new();
+        let stores = LibraryStores { dir: "browser".into(), catalog: Box::new(files2.store()), files: Box::new(files2.store()), on_disk: false };
+        s2.open_library_in(stores, true).unwrap();
+        assert_eq!(s2.catalog.photo(id).unwrap().rating, 5, "the rating survived");
+    }
+
     #[test]
     fn library_survives_reload_through_flushes() {
         let mut disk = BTreeMap::new();

apps/lightcraft-web/src/lib.rs

@@ -16,6 +16,7 @@
 #![forbid(unsafe_code)]
 #![deny(clippy::unwrap_used, clippy::expect_used, clippy::panic, clippy::unimplemented, clippy::todo, clippy::unreachable)]
 
+pub mod backup;
 pub mod bench;
 pub mod files;
 pub mod store;
@@ -24,6 +25,8 @@ pub mod wire;
 #[cfg(target_arch = "wasm32")]
 mod backend;
 #[cfg(target_arch = "wasm32")]
+mod safety;
+#[cfg(target_arch = "wasm32")]
 mod web;
 #[cfg(target_arch = "wasm32")]
 mod workers;

apps/lightcraft-web/src/safety.rs

@@ -0,0 +1,256 @@
+//! Keeping a library in the browser safe: notices the user must see (a failed save, storage the
+//! browser may evict, a file that couldn't be stored), one tab at a time per library, a message
+//! instead of a dead page after a panic, and backup / restore of the whole library
+//! ([`crate::backup`]).
+
+use std::cell::RefCell;
+use std::collections::HashMap;
+
+use js_sys::{Reflect, Uint8Array};
+use wasm_bindgen::JsCast;
+use wasm_bindgen::prelude::*;
+use wasm_bindgen_futures::JsFuture;
+
+use crate::backend::Backend;
+use crate::backup::{
+    ACTIVE_LIBRARY, README, ZipWriter, data_offset, find_central, original_entry, parse_central, restore_key, restored_dir_name, tail_len,
+    valid_hash, verify,
+};
+use crate::files::{Files, LIBRARY_FILES};
+use crate::store::storage_key;
+
+thread_local! {
+    /// Messages for the user, shown by the app on its next frame.
+    static NOTICES: RefCell<Vec<String>> = const { RefCell::new(Vec::new()) };
+}
+
+/// Queue a message for the user (shown for several seconds; also logged).
+pub fn notice(text: impl Into<String>) {
+    let text = text.into();
+    log::warn!("{text}");
+    NOTICES.with(|n| n.borrow_mut().push(text));
+    crate::web::request_repaint();
+}
+
+/// Messages queued since the last call.
+pub fn take_notices() -> Vec<String> {
+    NOTICES.with(|n| std::mem::take(&mut *n.borrow_mut()))
+}
+
+fn document() -> Option<web_sys::Document> {
+    web_sys::window()?.document()
+}
+
+/// Ask the user (the browser's own confirm box). `false` when it can't be shown.
+pub fn confirm(text: &str) -> bool {
+    web_sys::window().and_then(|w| w.confirm_with_message(text).ok()).unwrap_or(false)
+}
+
+/// Cover the page with a message (the app can't continue, or must not start).
+pub fn show_blocking(text: &str) {
+    let Some(doc) = document() else { return };
+    let el = match doc.get_element_by_id("lightcraft_blocking") {
+        Some(el) => el,
+        None => {
+            let Ok(el) = doc.create_element("div") else { return };
+            el.set_id("lightcraft_blocking");
+            let _ = el.set_attribute(
+                "style",
+                "position:fixed;inset:0;z-index:10;display:flex;align-items:center;justify-content:center;padding:32px;\
+                 background:#1c1c1c;color:#e0e0e0;font:15px/1.5 system-ui,-apple-system,'Segoe UI',sans-serif;text-align:center;white-space:pre-line",
+            );
+            if let Some(body) = doc.body() {
+                let _ = body.append_child(&el);
+            }
+            el
+        }
+    };
+    el.set_text_content(Some(text));
+    if let Some(loading) = doc.get_element_by_id("lightcraft_loading") {
+        loading.remove();
+    }
+}
+
+/// `panic = "abort"` on wasm: a panic ends the module. Say so on the page instead of leaving a
+/// frozen canvas, and say that the stored library is intact.
+pub fn install_panic_hook() {
+    std::panic::set_hook(Box::new(|info| {
+        let msg = match (info.payload().downcast_ref::<&str>(), info.payload().downcast_ref::<String>()) {
+            (Some(s), _) => (*s).to_string(),
+            (_, Some(s)) => s.clone(),
+            _ => "unknown error".into(),
+        };
+        let at = info.location().map(|l| format!(" at {}:{}", l.file(), l.line())).unwrap_or_default();
+        log::error!("LightCraft panicked{at}: {msg}");
+        show_blocking(&format!(
+            "LightCraft stopped after an internal error:\n{msg}\n\nThe library saved in this browser is kept. Reload the page to continue.\n\
+             If it happens again right away, a photo may be the cause: reload with ?workers=0 or report the error."
+        ));
+    }));
+}
+
+/// The name of the lock that keeps a library to one tab.
+const TAB_LOCK: &str = "lightcraft-library";
+
+/// Hold the library lock for as long as this page lives (Web Locks API). `Some(true)`: ours;
+/// `Some(false)`: another tab of this site has it; `None`: the browser can't tell (no Web Locks).
+pub async fn acquire_tab_lock() -> Option<bool> {
+    let nav = Reflect::get(&js_sys::global(), &"navigator".into()).ok()?;
+    let locks = Reflect::get(&nav, &"locks".into()).ok().filter(|l| !l.is_undefined() && !l.is_null())?;
+    let request: js_sys::Function = Reflect::get(&locks, &"request".into()).ok()?.dyn_into().ok()?;
+    let opts = js_sys::Object::new();
+    Reflect::set(&opts, &"ifAvailable".into(), &true.into()).ok()?;
+    let granted = js_sys::Promise::new(&mut |resolve, _reject| {
+        let cb = Closure::once_into_js(move |lock: JsValue| -> JsValue {
+            let ours = !lock.is_null() && !lock.is_undefined();
+            let _ = resolve.call1(&JsValue::NULL, &ours.into());
+            // keep the lock until the page goes away: a promise that never settles
+            if ours { js_sys::Promise::new(&mut |_, _| {}).into() } else { JsValue::NULL }
+        });
+        if let Err(e) = request.call3(&locks, &TAB_LOCK.into(), &opts, &cb) {
+            log::warn!("Web Locks request failed: {e:?}");
+        }
+    });
+    JsFuture::from(granted).await.ok().map(|v| v.is_truthy())
+}
+
+/// Offer a blob as a download named `name`.
+pub fn download_blob(name: &str, blob: &web_sys::Blob) -> Result<(), String> {
+    let e = |e: JsValue| format!("download failed: {e:?}");
+    let url = web_sys::Url::create_object_url_with_blob(blob).map_err(e)?;
+    let doc = document().ok_or("no document")?;
+    let a: web_sys::HtmlAnchorElement = doc.create_element("a").map_err(e)?.unchecked_into();
+    a.set_href(&url);
+    a.set_download(name);
+    a.click();
+    // revoke once the download has started
+    let revoke = Closure::once_into_js(move || {
+        let _ = web_sys::Url::revoke_object_url(&url);
+    });
+    if let Some(w) = web_sys::window() {
+        let _ = w.set_timeout_with_callback_and_timeout_and_arguments_0(revoke.unchecked_ref(), 60_000);
+    }
+    Ok(())
+}
+
+/// File ▸ Back Up Library…: a zip of the library files (as the app has them, saved or not) and
+/// every original in storage, built entry by entry into the browser's memory (outside the wasm
+/// heap) and downloaded. `names`: content hash → the photo's file name.
+pub async fn backup(files: Files, backend: Backend, names: HashMap<String, String>) -> Result<(usize, f64), String> {
+    let parts = js_sys::Array::new();
+    let mut zip = ZipWriter::default();
+    let mut bytes = 0f64;
+    let mut add = |zip: &mut ZipWriter, name: &str, data: &[u8]| -> Result<(), String> {
+        let header = zip.entry(name, data)?;
+        parts.push(&Uint8Array::from(&header[..]));
+        parts.push(&Uint8Array::from(data));
+        bytes += (header.len() + data.len()) as f64;
+        Ok(())
+    };
+    add(&mut zip, "README.txt", README.as_bytes())?;
+    for name in LIBRARY_FILES {
+        if let Some(d) = files.get(name) {
+            add(&mut zip, &format!("library/{name}"), &d)?;
+        }
+    }
+    let mut originals = 0;
+    for hash in backend.list("originals").await? {
+        if !valid_hash(&hash) {
+            continue;
+        }
+        match backend.read(&storage_key(&hash)).await {
+            Ok(Some(data)) => {
+                let name = names.get(&hash).map_or("original", String::as_str);
+                add(&mut zip, &original_entry(&hash, name), &data)?;
+                originals += 1;
+            }
+            Ok(None) => {}
+            Err(e) => return Err(format!("reading an original from browser storage: {e}")),
+        }
+    }
+    let tail = zip.finish()?;
+    parts.push(&Uint8Array::from(&tail[..]));
+    let opts = web_sys::BlobPropertyBag::new();
+    opts.set_type("application/zip");
+    let blob = web_sys::Blob::new_with_u8_array_sequence_and_options(&parts, &opts).map_err(|e| format!("{e:?}"))?;
+    let day: String = String::from(js_sys::Date::new_0().to_iso_string()).chars().take(10).collect();
+    download_blob(&format!("lightcraft-library-backup-{day}.zip"), &blob)?;
+    Ok((originals, bytes + tail.len() as f64))
+}
+
+/// Bytes `start..end` of a picked file.
+async fn read_range(file: &web_sys::File, start: u64, end: u64) -> Result<Vec<u8>, String> {
+    let blob = file.slice_with_f64_and_f64(start as f64, end as f64).map_err(|e| format!("{e:?}"))?;
+    let buf = JsFuture::from(blob.array_buffer()).await.map_err(|e| format!("{e:?}"))?;
+    Ok(Uint8Array::new(&buf).to_vec())
+}
+
+/// Restore a backup into a new library folder (nothing in storage is deleted or overwritten),
+/// then point [`ACTIVE_LIBRARY`] at it. Returns the folder's name; the caller reloads the page.
+pub async fn restore(file: web_sys::File, backend: Backend) -> Result<String, String> {
+    let len = file.size() as u64;
+    let tail = read_range(&file, len - tail_len(len), len).await?;
+    let (cd_offset, cd_size) = find_central(&tail)?;
+    let cd = read_range(&file, cd_offset, cd_offset + cd_size).await?;
+    let entries = parse_central(&cd)?;
+    if !entries.iter().any(|e| e.name == "library/catalog.snap" || e.name == "library/catalog.log") {
+        return Err("this isn't a LightCraft library backup (no library/catalog files)".into());
+    }
+    let dir = restored_dir_name(js_sys::Date::now());
+    let mut written = 0usize;
+    for e in &entries {
+        let Some(key) = restore_key(&e.name, &dir) else { continue };
+        // originals are named by their content: one already stored is the same file
+        if key.starts_with("originals/") && backend.exists(&key).await? {
+            continue;
+        }
+        let local = read_range(&file, e.header, e.header + 30).await?;
+        let start = data_offset(e, &local)?;
+        let data = read_range(&file, start, start + e.size).await?;
+        verify(e, &data)?;
+        backend.write(&key, &data).await.map_err(|err| format!("storing {}: {err}", e.name))?;
+        written += 1;
+    }
+    backend.write(ACTIVE_LIBRARY, dir.as_bytes()).await?;
+    log::info!("lightcraft: restored {written} files into {dir}");
+    Ok(dir)
+}
+
+/// File ▸ Restore Library from Backup…: confirm, pick the zip, restore, reload.
+pub fn pick_and_restore(backend: Backend, before_reload: impl FnOnce() + 'static) {
+    let ok = confirm(
+        "Restore a LightCraft library backup?\n\nThe backup becomes the library in this browser and the page reloads. \
+         The current library is not deleted: it stays in browser storage.",
+    );
+    if !ok {
+        return;
+    }
+    let Some(doc) = document() else { return };
+    let Ok(input) = doc.create_element("input").map(|e| e.unchecked_into::<web_sys::HtmlInputElement>()) else { return };
+    input.set_type("file");
+    input.set_accept(".zip,application/zip");
+    let inp = input.clone();
+    let mut before_reload = Some(before_reload);
+    let on_change = Closure::<dyn FnMut()>::new(move || {
+        let Some(file) = inp.files().and_then(|f| f.get(0)) else { return };
+        let backend = backend.clone();
+        let before = before_reload.take();
+        notice(format!("Restoring {}…", file.name()));
+        wasm_bindgen_futures::spawn_local(async move {
+            match restore(file, backend).await {
+                Ok(_) => {
+                    if let Some(f) = before {
+                        f();
+                    }
+                    if let Some(w) = web_sys::window() {
+                        let _ = w.location().reload();
+                    }
+                }
+                Err(e) => notice(format!("Restore failed: {e}. Nothing was changed: the current library is still in use.")),
+            }
+        });
+    });
+    input.set_onchange(Some(on_change.as_ref().unchecked_ref()));
+    on_change.forget();
+    input.click();
+}

apps/lightcraft-web/src/web.rs

@@ -15,16 +15,21 @@ use wasm_bindgen::JsCast;
 use wasm_bindgen::prelude::*;
 
 use crate::backend::Backend;
+use crate::backup::{ACTIVE_LIBRARY, DEFAULT_LIBRARY_DIR, valid_library_dir};
 use crate::bench::Bench;
 use crate::files::{Files, FlushOp, LIBRARY_FILES};
+use crate::safety::{self, notice};
 use crate::store::{Originals, content_hash, download_name, storage_key};
 use crate::wire::ThumbIndex;
 use crate::workers::{THUMB_INDEX, Workers};
 
 const ACCEPT: &str = ".jpg,.jpeg,.png,.tif,.tiff,.webp,.dng,.cr2,.nef,.arw,.psd,.jxl,.gif,.bmp";
 
-/// Where the library files live in browser storage.
-const LIBRARY_DIR: &str = "library";
+/// After a failed save, wait this long before trying again (ms).
+const SAVE_RETRY_MS: f64 = 2000.0;
+
+/// How long a notice stays on screen (s).
+const NOTICE_SECS: f64 = 8.0;
 
 /// How often view state, UI prefs and the thumbnail index are saved (ms).
 const SAVE_EVERY_MS: f64 = 1000.0;
@@ -45,8 +50,18 @@ fn set_status(text: &str) {
     }
 }
 
-fn library_key(name: &str) -> String {
-    format!("{LIBRARY_DIR}/{name}")
+/// Storage key of library file `name` in library folder `dir`.
+fn library_key(dir: &str, name: &str) -> String {
+    format!("{dir}/{name}")
+}
+
+/// Repaint the app (notices from async tasks).
+pub(crate) fn request_repaint() {
+    CTX.with(|c| {
+        if let Some(c) = c.borrow().as_ref() {
+            c.request_repaint();
+        }
+    });
 }
 
 /// URL options (`?bench&store=idb&workers=2&reset`).
@@ -86,8 +101,9 @@ async fn store_file(originals: Originals, backend: Option<Backend>, name: String
     if let Some(b) = &backend
         && let Err(e) = b.write(&storage_key(&hash), &bytes).await
     {
-        // still importable for this session; it won't survive a reload
-        log::error!("storing {name} in browser storage failed: {e}");
+        // a photo whose bytes aren't stored would be gone after a reload: don't add it
+        notice(format!("{name} was not added: browser storage refused it ({e}). Free up space or back up and clear old photos."));
+        return;
     }
     originals.added(&name, &hash, Arc::from(bytes));
     ctx.request_repaint();
@@ -148,8 +164,42 @@ fn download(path: &str, bytes: &[u8]) -> Result<(), String> {
     Ok(())
 }
 
-fn services(originals: Originals, backend: Option<Backend>, ctx: egui::Context) -> Services {
+fn services(originals: Originals, backend: Option<Backend>, files: Files, frozen: Rc<Cell<bool>>, ctx: egui::Context) -> Services {
+    let (backup_backend, backup_files) = (backend.clone(), files);
+    let restore_backend = backend.clone();
     Services {
+        backup_library: Some(Box::new(move |session: &mut Session| {
+            let Some(b) = backup_backend.clone() else { return Err("nothing is stored in this browser session (?store=memory)".into()) };
+            // the photos' own names for the originals in the zip
+            let names: std::collections::HashMap<String, String> = session
+                .catalog
+                .photos()
+                .filter_map(|p| match &p.source {
+                    Source::File { path } => crate::store::hash_of_path(path).map(|h| (h.to_string(), p.file_name.clone())),
+                    _ => None,
+                })
+                .collect();
+            let files = backup_files.clone();
+            notice("Backing up the library… (the download starts when it's ready)");
+            wasm_bindgen_futures::spawn_local(async move {
+                match safety::backup(files, b, names).await {
+                    Ok((n, bytes)) => notice(format!(
+                        "Library backed up: {n} original{} ({:.1} MB). Keep the file somewhere safe.",
+                        if n == 1 { "" } else { "s" },
+                        bytes / 1e6
+                    )),
+                    Err(e) => notice(format!("Backup failed: {e}")),
+                }
+            });
+            Ok(json!({"started": true}))
+        })),
+        restore_library: Some(Box::new(move |_session: &mut Session| {
+            let Some(b) = restore_backend.clone() else { return Err("nothing is stored in this browser session (?store=memory)".into()) };
+            let frozen = frozen.clone();
+            // once the backup is in place, stop saving the old library (the page reloads)
+            safety::pick_and_restore(b, move || frozen.set(true));
+            Ok(json!({"started": true}))
+        })),
         pick_files: Some(Box::new(move || {
             open_picker(originals.clone(), backend.clone(), ctx.clone());
             Vec::new() // files arrive asynchronously and are imported on a later frame
@@ -176,21 +226,29 @@ fn services(originals: Originals, backend: Option<Backend>, ctx: egui::Context)
     }
 }
 
-/// Write dirty library files to storage, in order, until none are left.
-async fn flush(files: Files, backend: Backend, flushing: Rc<Cell<bool>>) {
+/// Write dirty library files to storage, in order, until none are left. A failure (quota,
+/// storage cleared) is recorded in `files` — the catalog then reports changes as unsaved instead
+/// of accepting them silently — and retried after [`SAVE_RETRY_MS`].
+async fn flush(files: Files, backend: Backend, dir: String, flushing: Rc<Cell<bool>>, failed_at: Rc<Cell<f64>>) {
     'outer: loop {
         let ops = files.take_dirty();
         if ops.is_empty() {
+            if files.error().is_some() {
+                log::info!("lightcraft: saving works again");
+            }
+            files.set_error(None);
             break;
         }
         for (i, op) in ops.iter().enumerate() {
             let r = match op {
-                FlushOp::Write { name, data } => backend.write(&library_key(name), data).await,
-                FlushOp::Append { name, offset, data } => backend.write_at(&library_key(name), Some(*offset), data).await,
+                FlushOp::Write { name, data } => backend.write(&library_key(&dir, name), data).await,
+                FlushOp::Append { name, offset, data } => backend.write_at(&library_key(&dir, name), Some(*offset), data).await,
             };
             if let Err(e) = r {
                 log::error!("saving {} failed: {e}", op.name());
                 files.failed(&ops[i..]);
+                files.set_error(Some(e));
+                failed_at.set(perf_now());
                 break 'outer;
             }
         }
@@ -204,6 +262,8 @@ struct Boot {
     backend: Option<Backend>,
     files: Files,
     index: ThumbIndex,
+    /// The library folder in storage (`library`, or a restored backup's).
+    lib_dir: String,
 }
 
 async fn boot(opts: Options) -> Boot {
@@ -221,15 +281,32 @@ async fn boot(opts: Options) -> Boot {
     };
     let files = Files::default();
     let mut index = ThumbIndex::default();
+    let mut lib_dir = DEFAULT_LIBRARY_DIR.to_string();
     if let Some(b) = &backend {
         if opts.reset {
-            match b.clear().await {
-                Ok(()) => log::info!("lightcraft: storage cleared (?reset)"),
-                Err(e) => log::error!("clearing storage: {e}"),
+            // everything this site keeps in the browser, photos included: never without asking
+            let ok = safety::confirm(
+                "?reset deletes the LightCraft library stored in this browser, including every imported photo. \
+                 This can't be undone. Delete it?",
+            );
+            if ok {
+                match b.clear().await {
+                    Ok(()) => log::info!("lightcraft: storage cleared (?reset)"),
+                    Err(e) => log::error!("clearing storage: {e}"),
+                }
+            } else {
+                log::info!("lightcraft: ?reset declined; storage kept");
+            }
+        }
+        // a restored backup lives in its own folder (see `backup`)
+        if let Ok(Some(d)) = b.read(ACTIVE_LIBRARY).await {
+            let d = String::from_utf8_lossy(&d).trim().to_string();
+            if valid_library_dir(&d) {
+                lib_dir = d;
             }
         }
         for name in LIBRARY_FILES {
-            match b.read(&library_key(name)).await {
+            match b.read(&library_key(&lib_dir, name)).await {
                 Ok(Some(data)) => files.preload(name, data),
                 Ok(None) => {}
                 Err(e) => log::error!("reading {name}: {e}"),
@@ -238,7 +315,14 @@ async fn boot(opts: Options) -> Boot {
         if let Ok(Some(j)) = b.read(THUMB_INDEX).await {
             index = ThumbIndex::from_json(&j);
         }
-        crate::backend::request_persistence();
+        crate::backend::request_persistence(|granted| {
+            if !granted {
+                notice(
+                    "This browser may delete LightCraft's library when it runs short of space (persistent storage wasn't granted). \
+                     Keep your original photos elsewhere and use File ▸ Back Up Library… now and then.",
+                );
+            }
+        });
         // thumbnails stored without an index entry (index saved late, or lost): delete them
         let b2 = b.clone();
         let known: std::collections::HashSet<String> = b
@@ -266,7 +350,7 @@ async fn boot(opts: Options) -> Boot {
         index.len(),
         index.total() as f64 / 1e6
     );
-    Boot { opts, backend, files, index }
+    Boot { opts, backend, files, index, lib_dir }
 }
 
 struct WebApp {
@@ -276,6 +360,11 @@ struct WebApp {
     backend: Option<Backend>,
     workers: Option<Workers>,
     flushing: Rc<Cell<bool>>,
+    /// When the last save to storage failed (ms; 0 = never).
+    flush_failed_at: Rc<Cell<f64>>,
+    /// Saving stopped (a restored backup is about to replace this library: the page reloads).
+    frozen: Rc<Cell<bool>>,
+    lib_dir: String,
     bench: Option<Bench>,
     first_frame_logged: bool,
     last_save: f64,
@@ -284,13 +373,13 @@ struct WebApp {
 
 impl WebApp {
     fn new(cc: &eframe::CreationContext<'_>, boot: Boot) -> Self {
-        let Boot { opts, backend, files, index } = boot;
+        let Boot { opts, backend, files, index, lib_dir } = boot;
         let originals = Originals::default();
         let t = perf_now();
         let mut session = Session::new();
         originals.install(&mut session);
         let stores = LibraryStores {
-            dir: format!("browser:{}/{LIBRARY_DIR}", backend.as_ref().map_or("memory", |b| b.kind())).into(),
+            dir: format!("browser:{}/{lib_dir}", backend.as_ref().map_or("memory", |b| b.kind())).into(),
             catalog: Box::new(files.store()),
             files: Box::new(files.store()),
             on_disk: false,
@@ -319,9 +408,16 @@ impl WebApp {
                 });
             }
         }
+        if backend.is_some() {
+            notice(
+                "LightCraft in the browser is experimental. Your library is kept in this browser's storage: keep your original photos \
+                 elsewhere and back up with File ▸ Back Up Library….",
+            );
+        }
         // previews are large (≤ 2560 px, f32): keep few in a 32-bit address space
         session.media.preview_capacity = 3;
-        let mut app = LightcraftApp::new(session, services(originals.clone(), backend.clone(), cc.egui_ctx.clone()));
+        let frozen = Rc::new(Cell::new(false));
+        let mut app = LightcraftApp::new(session, services(originals.clone(), backend.clone(), files.clone(), frozen.clone(), cc.egui_ctx.clone()));
         let ui_written = files.get("ui.json").unwrap_or_default();
         if let Ok(ui) = serde_json::from_slice::<UiState>(&ui_written) {
             app.ui = ui;
@@ -347,6 +443,9 @@ impl WebApp {
             backend,
             workers,
             flushing: Rc::new(Cell::new(false)),
+            flush_failed_at: Rc::new(Cell::new(0.0)),
+            frozen,
+            lib_dir,
             bench: opts.bench.then(|| Bench::new(origin)),
             first_frame_logged: false,
             last_save: 0.0,
@@ -408,6 +507,9 @@ impl WebApp {
 
     /// Save view state, UI prefs and the thumbnail index now and then; flush dirty files.
     fn save(&mut self) {
+        if self.frozen.get() {
+            return;
+        }
         let now = perf_now();
         if now - self.last_save >= SAVE_EVERY_MS {
             self.last_save = now;
@@ -429,12 +531,16 @@ impl WebApp {
                 });
             }
         }
+        // after a failure, retry every couple of seconds rather than every frame
+        let backing_off = self.files.error().is_some() && now - self.flush_failed_at.get() < SAVE_RETRY_MS;
         if let Some(b) = &self.backend
             && self.files.is_dirty()
             && !self.flushing.get()
+            && !backing_off
         {
             self.flushing.set(true);
-            wasm_bindgen_futures::spawn_local(flush(self.files.clone(), b.clone(), self.flushing.clone()));
+            let (files, dir, flushing, failed_at) = (self.files.clone(), self.lib_dir.clone(), self.flushing.clone(), self.flush_failed_at.clone());
+            wasm_bindgen_futures::spawn_local(flush(files, b.clone(), dir, flushing, failed_at));
         }
     }
 }
@@ -464,8 +570,10 @@ impl WebApp {
         let (orig_n, orig_bytes) = self.originals.usage();
         json!({
             "storage": self.backend.as_ref().map_or("memory", |b| b.kind()),
+            "library": self.lib_dir,
             "dirty": self.files.is_dirty(),
             "flushing": self.flushing.get(),
+            "saveError": self.files.error(),
             "workers": {"alive": alive, "ready": ready, "remoteJobs": remote, "inlineJobs": inline},
             "originalsInMemory": orig_n,
             "originalBytesInMemory": orig_bytes,
@@ -490,6 +598,10 @@ impl WebApp {
 
 impl eframe::App for WebApp {
     fn logic(&mut self, ctx: &egui::Context, _frame: &mut eframe::Frame) {
+        for text in safety::take_notices() {
+            let now = ctx.input(|i| i.time);
+            self.app.ui.toast = Some((text, now + NOTICE_SECS));
+        }
         self.run_inbox();
         self.import_dropped(ctx);
         self.load_originals(ctx);
@@ -527,9 +639,18 @@ impl eframe::App for WebApp {
 #[wasm_bindgen]
 pub fn start() {
     eframe::WebLogger::init(log::LevelFilter::Info).ok();
+    safety::install_panic_hook();
     log::info!("lightcraft: wasm instantiated at {:.0} ms", perf_now());
     let opts = Options::from_url();
     wasm_bindgen_futures::spawn_local(async move {
+        // one tab per library: two would each keep their own copy and overwrite each other's saves
+        if opts.store != "memory" && safety::acquire_tab_lock().await == Some(false) {
+            safety::show_blocking(
+                "LightCraft is already open in another tab or window of this browser.\n\n\
+                 Switch to that tab, or close it and reload this page. (Two tabs would overwrite each other's changes.)",
+            );
+            return;
+        }
         let Some(canvas) = window()
             .and_then(|w| w.document())
             .and_then(|d| d.get_element_by_id("lightcraft_canvas"))

apps/lightcraft-web/src/wire.rs

@@ -15,10 +15,9 @@ use std::sync::Arc;
 
 use lightcraft_engine::catalog::Source;
 use lightcraft_engine::develop::{DevelopSettings, EmbeddedLens};
-use lightcraft_engine::media::{MediaCache, RenderJob, SourceLevel, SourceRef};
+use lightcraft_engine::media::{DecodedSource, MediaCache, RenderJob, SourceLevel, SourceRef};
 use lightcraft_engine::pipeline::{Quality, RenderRequest, Rendered, SourceInfo, StageCache};
 use lightcraft_preview::Lru;
-use lightcraft_raster::Rgb32f;
 use serde::{Deserialize, Serialize};
 
 use crate::store::hash_of_path;
@@ -31,6 +30,8 @@ pub struct WireJob {
     /// Decode the source at most this long.
     pub max_edge: usize,
     pub raw: bool,
+    #[serde(default)]
+    pub relative_wb: bool,
     pub as_shot_temp: f64,
     pub as_shot_tint: f64,
     pub lens: Option<EmbeddedLens>,
@@ -55,7 +56,7 @@ impl WireJob {
     pub fn from_job(job: &RenderJob, thumb_cached: bool, view: &str) -> WireJob {
         let max_edge = match &job.source {
             SourceRef::Demo { max_edge, .. } | SourceRef::File { max_edge, .. } => *max_edge,
-            SourceRef::Loaded(img) => img.width.max(img.height),
+            SourceRef::Loaded(img) => img.image.width.max(img.image.height),
             SourceRef::Smart { .. } => 2560,
         };
         WireJob {
@@ -63,6 +64,7 @@ impl WireJob {
             origin: job.origin.clone(),
             max_edge,
             raw: job.info.raw,
+            relative_wb: job.info.relative_wb,
             as_shot_temp: job.info.as_shot_temp,
             as_shot_tint: job.info.as_shot_tint,
             lens: job.info.lens,
@@ -79,7 +81,14 @@ impl WireJob {
     }
 
     pub fn info(&self) -> SourceInfo {
-        SourceInfo { raw: self.raw, as_shot_temp: self.as_shot_temp, as_shot_tint: self.as_shot_tint, lens: self.lens }
+        SourceInfo {
+            raw: self.raw,
+            as_shot_temp: self.as_shot_temp,
+            as_shot_tint: self.as_shot_tint,
+            lens: self.lens,
+            relative_wb: self.relative_wb,
+            ..Default::default()
+        }
     }
 
     pub fn request(&self) -> RenderRequest {
@@ -119,7 +128,7 @@ const WORKER_SOURCE_BYTES: usize = 192 << 20;
 
 /// The synchronous part of a worker: decoded-source cache + rendering.
 pub struct WorkerCore {
-    sources: Lru<String, Arc<Rgb32f>>,
+    sources: Lru<String, DecodedSource>,
     media: MediaCache,
     stages: HashMap<String, Arc<StageCache>>,
 }
@@ -150,21 +159,25 @@ impl WorkerCore {
             Some(s) => s,
             None => {
                 let src = match (&job.origin, original) {
-                    (Source::File { .. }, Some(bytes)) => Arc::new(lightcraft_engine::files::load_bytes(bytes, job.max_edge)?.0),
+                    (Source::File { .. }, Some(bytes)) => {
+                        let (image, info) = lightcraft_engine::files::load_bytes(bytes, job.max_edge)?;
+                        DecodedSource::new(Arc::new(image), Some(info))
+                    }
                     (Source::File { path }, None) => return Err(format!("{path}: original not found in browser storage")),
-                    (origin @ Source::Demo { .. }, _) => self.media.origin_ref(origin, job.max_edge).load()?,
+                    (origin @ Source::Demo { .. }, _) => self.media.origin_ref(origin, job.max_edge).load_source()?,
                 };
-                let cost = src.width * src.height * 12 + 64;
+                let cost = src.image.width * src.image.height * 12 + 64;
                 self.sources.insert(key, src.clone(), cost);
                 src
             }
         };
+        let info = src.info_or(job.info());
         Ok(match &job.stages {
             Some(view) => {
                 let st = self.stages.entry(view.clone()).or_default().clone();
-                lightcraft_engine::pipeline::render_cached(&src, &job.info(), &job.settings, &job.request(), &st)
+                lightcraft_engine::pipeline::render_cached(&src.image, &info, &job.settings, &job.request(), &st)
             }
-            None => lightcraft_engine::pipeline::render(&src, &job.info(), &job.settings, &job.request()),
+            None => lightcraft_engine::pipeline::render(&src.image, &info, &job.settings, &job.request()),
         })
     }
 }
@@ -295,6 +308,7 @@ mod tests {
             origin,
             max_edge: 512,
             raw: false,
+            relative_wb: false,
             as_shot_temp: 6500.0,
             as_shot_tint: 0.0,
             lens: None,

apps/lightcraft/Cargo.toml

@@ -10,7 +10,7 @@ default-run = "lightcraft"
 workspace = true
 
 [dependencies]
-lightcraft-engine = { workspace = true }
+lightcraft-engine = { workspace = true, features = ["sam"] }
 lightcraft-sysmem = { workspace = true }
 lightcraft-ui-egui = { workspace = true }
 lightcraft-codecs = { workspace = true }

apps/lightcraft/src/main.rs

@@ -71,17 +71,45 @@ impl eframe::App for App {
     }
 }
 
-fn config_dir() -> Option<std::path::PathBuf> {
-    if cfg!(target_os = "macos") {
-        std::env::var_os("HOME").map(|h| std::path::PathBuf::from(h).join("Library/Application Support/LightCraft"))
-    } else if cfg!(windows) {
-        std::env::var_os("APPDATA").map(|a| std::path::PathBuf::from(a).join("LightCraft"))
-    } else {
-        std::env::var_os("XDG_CONFIG_HOME")
-            .map(std::path::PathBuf::from)
-            .or_else(|| std::env::var_os("HOME").map(|h| std::path::PathBuf::from(h).join(".config")))
-            .map(|c| c.join("lightcraft"))
+/// The window's renderer (egui-wgpu): eframe's defaults, with LightCraft's backend choice — DX12
+/// alone on Windows unless `LIGHTCRAFT_GPU_BACKEND` / `WGPU_BACKEND` say otherwise (issue #136:
+/// with Vulkan in the set, wgpu loads the Vulkan driver even when it then picks DX12).
+fn window_wgpu_options() -> eframe::egui_wgpu::WgpuConfiguration {
+    let mut c = eframe::egui_wgpu::WgpuConfiguration::default();
+    if let eframe::egui_wgpu::WgpuSetup::CreateNew(n) = &mut c.wgpu_setup {
+        n.instance_descriptor.backends = lightcraft_engine::gpu::backend::window_backends();
     }
+    c
+}
+
+/// Written while the GPU compute device is created, removed once that returned
+/// (`lightcraft_gpu::backend::set_init_marker`). Not with `LIGHTCRAFT_NO_PREFS` (tests, scripts).
+fn gpu_marker_path() -> Option<std::path::PathBuf> {
+    if std::env::var_os("LIGHTCRAFT_NO_PREFS").is_some() {
+        return None;
+    }
+    config_dir().map(|d| d.join("gpu-init.marker"))
+}
+
+/// Arm the GPU crash sentinel; if the previous launch left it behind (it died inside the GPU
+/// driver while creating the device), the notice to show — GPU rendering then starts off.
+fn gpu_crash_check() -> Option<String> {
+    let marker = gpu_marker_path();
+    let left = marker.as_deref().and_then(lightcraft_engine::gpu::backend::take_init_marker);
+    lightcraft_engine::gpu::backend::set_init_marker(marker);
+    left.map(|what| gpu_crash_notice(&what))
+}
+
+fn gpu_crash_notice(what: &str) -> String {
+    format!(
+        "LightCraft closed unexpectedly while starting the GPU last time ({what}), so GPU rendering is now off and photos render on the CPU. \
+         To try the GPU again, turn on Settings ▸ Performance ▸ Use the GPU for rendering; to try another graphics backend, start LightCraft with \
+         LIGHTCRAFT_GPU_BACKEND=dx12, vulkan or off (see docs/gpu-pipeline.md → Troubleshooting)."
+    )
+}
+
+fn config_dir() -> Option<std::path::PathBuf> {
+    lightcraft_engine::camera_profiles::config_dir()
 }
 
 /// The saved UI state and app settings (`<config>/ui.json`), if any, and a warning for the user
@@ -202,7 +230,9 @@ impl PrefsWriter {
 
 fn services() -> Services {
     Services {
-        pick_folder: Some(Box::new(|| rfd::FileDialog::new().set_title("Open Library").pick_folder().map(|p| p.to_string_lossy().to_string()))),
+        pick_folder: Some(Box::new(|| {
+            rfd::FileDialog::new().set_title(lightcraft_ui_egui::i18n::tr("Open Library")).pick_folder().map(|p| p.to_string_lossy().to_string())
+        })),
         open_with: Some(Box::new(|path: &str, app: &str| {
             // spawned, never waited for: the editor runs alongside
             let app = app.trim();
@@ -254,7 +284,7 @@ fn services() -> Services {
         pick_files: Some(Box::new(|| {
             rfd::FileDialog::new()
                 .add_filter(
-                    "Photos",
+                    lightcraft_ui_egui::i18n::tr("Photos"),
                     &[
                         "jpg", "jpeg", "png", "tif", "tiff", "webp", "dng", "cr2", "cr3", "nef", "nrw", "arw", "raf", "orf", "rw2", "pef", "psd",
                         "jxl", "gif", "bmp",
@@ -268,8 +298,11 @@ fn services() -> Services {
         })),
         pick_preset_files: Some(Box::new(|| {
             rfd::FileDialog::new()
-                .set_title("Import Presets")
-                .add_filter("Presets & Profiles", &["lcpreset", "xmp", "lrtemplate", "zip", "dng", "lmp", "mplumpack", "cube"])
+                .set_title(lightcraft_ui_egui::i18n::tr("Import Presets"))
+                .add_filter(
+                    lightcraft_ui_egui::i18n::tr("Presets & Profiles"),
+                    &["lcpreset", "xmp", "lrtemplate", "zip", "dng", "lmp", "mplumpack", "cube"],
+                )
                 .pick_files()
                 .unwrap_or_default()
                 .into_iter()
@@ -278,24 +311,24 @@ fn services() -> Services {
         })),
         pick_tracklog: Some(Box::new(|| {
             rfd::FileDialog::new()
-                .set_title("Auto-Tag from Tracklog")
-                .add_filter("GPS Track Log", &["gpx"])
+                .set_title(lightcraft_ui_egui::i18n::tr("Auto-Tag from Tracklog"))
+                .add_filter(lightcraft_ui_egui::i18n::tr("GPS Track Log"), &["gpx"])
                 .pick_file()
                 .map(|p| vec![p.to_string_lossy().to_string()])
                 .unwrap_or_default()
         })),
         save_preset_file: Some(Box::new(|name: &str| {
             rfd::FileDialog::new()
-                .set_title("Export Presets")
-                .add_filter("LightCraft Preset", &["lcpreset"])
+                .set_title(lightcraft_ui_egui::i18n::tr("Export Presets"))
+                .add_filter(lightcraft_ui_egui::i18n::tr("LightCraft Preset"), &["lcpreset"])
                 .set_file_name(name)
                 .save_file()
                 .map(|p| p.to_string_lossy().to_string())
         })),
         pick_curve_preset_files: Some(Box::new(|| {
             rfd::FileDialog::new()
-                .set_title("Import Point Curve Presets")
-                .add_filter("Point Curve Presets", &["lccurve", "json"])
+                .set_title(lightcraft_ui_egui::i18n::tr("Import Point Curve Presets"))
+                .add_filter(lightcraft_ui_egui::i18n::tr("Point Curve Presets"), &["lccurve", "json"])
                 .pick_files()
                 .unwrap_or_default()
                 .into_iter()
@@ -304,8 +337,8 @@ fn services() -> Services {
         })),
         save_curve_preset_file: Some(Box::new(|name: &str| {
             rfd::FileDialog::new()
-                .set_title("Export Point Curve Presets")
-                .add_filter("Point Curve Presets", &["lccurve"])
+                .set_title(lightcraft_ui_egui::i18n::tr("Export Point Curve Presets"))
+                .add_filter(lightcraft_ui_egui::i18n::tr("Point Curve Presets"), &["lccurve"])
                 .set_file_name(name)
                 .save_file()
                 .map(|p| p.to_string_lossy().to_string())
@@ -316,6 +349,9 @@ fn services() -> Services {
         png: Some(Box::new(|img: &lightcraft_raster::Rgba8| {
             lightcraft_codecs::encode_png(&lightcraft_codecs::EncodeImage::rgba8(img), &lightcraft_codecs::EncodeMeta::default()).unwrap_or_default()
         })),
+        // the library is a folder on disk: backed up with the user's other files
+        backup_library: None,
+        restore_library: None,
     }
 }
 
@@ -366,10 +402,46 @@ OPTIONS:
   --control PORT   serve the JSON-lines control channel on 127.0.0.1:PORT (env LIGHTCRAFT_CONTROL_PORT;
                    see docs/control-protocol.md)
   --version, --help
+
+ENVIRONMENT:
+  LIGHTCRAFT_GPU_BACKEND=dx12|vulkan|metal|auto|off   graphics backend (default: DX12 on Windows, Metal on macOS,
+                   Vulkan on Linux; off = render on the CPU); else WGPU_BACKEND. LIGHTCRAFT_GPU=0: CPU rendering.
+  LIGHTCRAFT_SAM3_DIR=DIR   the SAM 3 model for Object / Describe masks (default: <settings folder>/models/sam3;
+                   optional: LightCraft offers to download it when first needed)
+  LIGHTCRAFT_SAM3_MIRRORS=URL,…   where to download the SAM 3 model from (base URLs, tried in order)
 ";
 
+/// Warnings and errors (failed commands, AI mask analysis) on stderr; `LIGHTCRAFT_LOG=info`
+/// (or `debug`) shows more.
+struct StderrLog(log::LevelFilter);
+
+impl log::Log for StderrLog {
+    fn enabled(&self, m: &log::Metadata) -> bool {
+        m.level() <= self.0 && (m.level() <= log::Level::Warn || m.target().starts_with("lightcraft"))
+    }
+    fn log(&self, r: &log::Record) {
+        if self.enabled(r.metadata()) {
+            eprintln!("lightcraft: {} {}: {}", r.level(), r.target(), r.args());
+        }
+    }
+    fn flush(&self) {}
+}
+
+fn install_log() {
+    let level = match std::env::var("LIGHTCRAFT_LOG").unwrap_or_default().as_str() {
+        "debug" => log::LevelFilter::Debug,
+        "info" => log::LevelFilter::Info,
+        _ => log::LevelFilter::Warn,
+    };
+    static LOGGER: std::sync::OnceLock<StderrLog> = std::sync::OnceLock::new();
+    if log::set_logger(LOGGER.get_or_init(|| StderrLog(level))).is_ok() {
+        log::set_max_level(level);
+    }
+}
+
 fn main() -> eframe::Result {
     lightcraft_engine::guard::install_hook(std::env::temp_dir().join("lightcraft-panics.log"));
+    install_log();
     alloc_release::install();
     let mut control_port: Option<u16> = std::env::var("LIGHTCRAFT_CONTROL_PORT").ok().and_then(|p| p.parse().ok());
     let mut files = Vec::new();
@@ -408,6 +480,11 @@ fn main() -> eframe::Result {
             .map(Into::into)
     });
     let library_dir = library_dir.or_else(lightcraft_engine::library::default_dir);
+    // GPU compute: off if the preference says so, or if the last launch died creating the device
+    // (issue #136) — before anything can create it
+    let gpu_crash = gpu_crash_check();
+    let gpu_on = prefs.as_ref().is_none_or(|u| u.settings.gpu) && gpu_crash.is_none();
+    lightcraft_engine::gpu::set_enabled(gpu_on);
     let options = eframe::NativeOptions {
         viewport: egui::ViewportBuilder::default()
             .with_title("LightCraft")
@@ -420,17 +497,25 @@ fn main() -> eframe::Result {
             .with_icon(app_icon())
             // Wayland matches the window to packaging/linux/ai.storyteller.lightcraft.desktop by this id
             .with_app_id(APP_ID),
+        wgpu_options: window_wgpu_options(),
         ..Default::default()
     };
     eframe::run_native(
         "LightCraft",
         options,
         Box::new(move |cc| {
-            let (session, problem) = open_session(in_memory, library_dir, seed_demo && files.is_empty());
+            let (mut session, problem) = open_session(in_memory, library_dir, seed_demo && files.is_empty());
+            // AI masks: the SAM 3 checkpoint (facebook/sam3) in <config>/models/sam3, or LIGHTCRAFT_SAM3_DIR
+            // (never required: without it, AI masks offer to download it; see docs/ai-masks.md)
+            session.segmenter.dir =
+                std::env::var_os("LIGHTCRAFT_SAM3_DIR").map(std::path::PathBuf::from).or_else(|| config_dir().map(|d| d.join("models").join("sam3")));
+            // the user's own download locations, one base URL per line (LIGHTCRAFT_SAM3_MIRRORS too)
+            session.segmenter.mirrors_file = config_dir().map(|d| d.join("models").join("sam3-mirrors.txt"));
             let mut app = LightcraftApp::new(session, services());
             if let Some(ui) = prefs {
                 app.ui = ui;
             }
+            lightcraft_ui_egui::i18n::set_language(app.ui.language);
             app.integrated_titlebar = cfg!(target_os = "macos");
             app.notices.extend(prefs_warning);
             // what's on disk now: only changes are written
@@ -440,6 +525,11 @@ fn main() -> eframe::Result {
                 keep_file: keep_prefs_file,
                 ..Default::default()
             };
+            // after the snapshot above, so the writer saves the switched-off preference
+            if let Some(notice) = gpu_crash {
+                app.ui.settings.gpu = false;
+                app.notices.push(notice);
+            }
             if let Some(port) = control_port {
                 let rx = control_server::start(port, cc.egui_ctx.clone());
                 app = app.with_control(rx);
@@ -497,6 +587,35 @@ mod tests {
         let _ = std::fs::remove_dir_all(&d);
     }
 
+    /// Issue #136: a GPU init marker left by a crashed launch is reported once and removed.
+    #[test]
+    fn gpu_crash_marker_is_reported_once() {
+        let d = dir("gpu-marker");
+        let m = d.join("gpu-init.marker");
+        assert_eq!(lightcraft_engine::gpu::backend::take_init_marker(&m), None);
+        std::fs::write(&m, "GPU device creation started (backends VULKAN | DX12)").unwrap();
+        let what = lightcraft_engine::gpu::backend::take_init_marker(&m).unwrap();
+        let notice = gpu_crash_notice(&what);
+        assert!(notice.contains("GPU rendering is now off") && notice.contains("Use the GPU for rendering"), "{notice}");
+        assert!(!m.exists());
+        let _ = std::fs::remove_dir_all(&d);
+    }
+
+    /// Issue #136: Windows windows render with DX12 alone (no Vulkan driver loaded) by default.
+    #[test]
+    fn window_backends_follow_the_platform_default() {
+        let eframe::egui_wgpu::WgpuSetup::CreateNew(n) = window_wgpu_options().wgpu_setup else { panic!("expected CreateNew") };
+        let b = n.instance_descriptor.backends;
+        if std::env::var_os("LIGHTCRAFT_GPU_BACKEND").is_none() && std::env::var_os("WGPU_BACKEND").is_none() {
+            if cfg!(windows) {
+                assert_eq!(b, eframe::wgpu::Backends::DX12);
+            } else if cfg!(target_os = "macos") {
+                assert_eq!(b, eframe::wgpu::Backends::METAL);
+            }
+        }
+        assert!(!b.is_empty());
+    }
+
     #[test]
     fn ui_json_is_written_atomically() {
         let d = dir("atomic");

apps/lightcraft/src/native_menu.rs

@@ -148,7 +148,7 @@ fn yields_to_text(sc: &str) -> bool {
 
 /// `&` marks a mnemonic in muda labels.
 fn label_text(s: &str) -> String {
-    s.replace('&', "&&")
+    lightcraft_ui_egui::i18n::tr(s).replace('&', "&&")
 }
 
 fn structure_of(bar: &[(String, Vec<MenuNode>)]) -> String {
@@ -171,7 +171,7 @@ fn structure_of(bar: &[(String, Vec<MenuNode>)]) -> String {
             out.push(';');
         }
     }
-    let mut s = String::new();
+    let mut s = format!("{};", lightcraft_ui_egui::i18n::language().code());
     for (t, items) in bar {
         s.push_str(t);
         walk(items, &mut s);
@@ -210,30 +210,30 @@ impl NativeMenu {
 
         // the application menu
         let app_menu = Submenu::new("LightCraft", true);
-        let about = MenuItem::with_id("app.about", "About LightCraft", true, None);
-        let settings = MenuItem::with_id(SETTINGS, app.ui.language.tr("Settings…"), true, accelerator(SETTINGS_KEY));
-        let quit = MenuItem::with_id(QUIT, "Quit LightCraft", true, accelerator("Cmd+Q"));
+        let about = MenuItem::with_id("app.about", lightcraft_ui_egui::i18n::tr("About LightCraft"), true, None);
+        let settings = MenuItem::with_id(SETTINGS, lightcraft_ui_egui::i18n::tr("Settings…"), true, accelerator(SETTINGS_KEY));
+        let quit = MenuItem::with_id(QUIT, lightcraft_ui_egui::i18n::tr("Quit LightCraft"), true, accelerator("Cmd+Q"));
         let _ = app_menu.append_items(&[
             &about,
             &PredefinedMenuItem::separator(),
             &settings,
             &PredefinedMenuItem::separator(),
-            &PredefinedMenuItem::services(None),
+            &PredefinedMenuItem::services(Some(lightcraft_ui_egui::i18n::tr("Services"))),
             &PredefinedMenuItem::separator(),
-            &PredefinedMenuItem::hide(Some("Hide LightCraft")),
-            &PredefinedMenuItem::hide_others(None),
-            &PredefinedMenuItem::show_all(None),
+            &PredefinedMenuItem::hide(Some(lightcraft_ui_egui::i18n::tr("Hide LightCraft"))),
+            &PredefinedMenuItem::hide_others(Some(lightcraft_ui_egui::i18n::tr("Hide Others"))),
+            &PredefinedMenuItem::show_all(Some(lightcraft_ui_egui::i18n::tr("Show All"))),
             &PredefinedMenuItem::separator(),
             &quit,
         ]);
         let _ = self.menu.append(&app_menu);
 
         for (title, nodes) in &bar {
-            let sub = Submenu::new(title, true);
-            if title == app.ui.language.tr("Window") {
+            let sub = Submenu::new(label_text(title), true);
+            if title == "Window" {
                 let _ = sub.append_items(&[
-                    &PredefinedMenuItem::minimize(None),
-                    &PredefinedMenuItem::maximize(Some("Zoom")),
+                    &PredefinedMenuItem::minimize(Some(lightcraft_ui_egui::i18n::tr("Minimize"))),
+                    &PredefinedMenuItem::maximize(Some(lightcraft_ui_egui::i18n::tr("Zoom"))),
                     &PredefinedMenuItem::separator(),
                 ]);
             }
@@ -245,15 +245,21 @@ impl NativeMenu {
                 .collect();
             let nodes = tidy_separators(nodes);
             self.append_nodes(&sub, &nodes);
-            if title == app.ui.language.tr("File") {
+            if title == "File" {
                 // ⌘W, the system's own item
-                let _ = sub.append_items(&[&PredefinedMenuItem::separator(), &PredefinedMenuItem::close_window(None)]);
+                let _ = sub.append_items(&[
+                    &PredefinedMenuItem::separator(),
+                    &PredefinedMenuItem::close_window(Some(lightcraft_ui_egui::i18n::tr("Close Window"))),
+                ]);
             }
-            if title == app.ui.language.tr("Window") {
-                let _ = sub.append_items(&[&PredefinedMenuItem::separator(), &PredefinedMenuItem::bring_all_to_front(None)]);
+            if title == "Window" {
+                let _ = sub.append_items(&[
+                    &PredefinedMenuItem::separator(),
+                    &PredefinedMenuItem::bring_all_to_front(Some(lightcraft_ui_egui::i18n::tr("Bring All to Front"))),
+                ]);
                 sub.set_as_windows_menu_for_nsapp();
             }
-            if title == app.ui.language.tr("Help") {
+            if title == "Help" {
                 sub.set_as_help_menu_for_nsapp();
             }
             let _ = self.menu.append(&sub);
@@ -282,12 +288,23 @@ impl NativeMenu {
                     let accel = shortcut.as_deref().filter(|s| !CONTEXTUAL.contains(s)).and_then(accelerator);
                     let handle = match checked {
                         Some(c) => {
-                            let it = CheckMenuItem::with_id(key.clone(), label_text(label), *enabled, *c, accel);
+                            let it = CheckMenuItem::with_id(
+                                key.clone(),
+                                lightcraft_ui_egui::menubar::display_item_label(id, params, label).replace('&', "&&"),
+                                *enabled,
+                                *c,
+                                accel,
+                            );
                             let _ = sub.append(&it);
                             Handle::Check(it)
                         }
                         None => {
-                            let it = MenuItem::with_id(key.clone(), label_text(label), *enabled, accel);
+                            let it = MenuItem::with_id(
+                                key.clone(),
+                                lightcraft_ui_egui::menubar::display_item_label(id, params, label).replace('&', "&&"),
+                                *enabled,
+                                accel,
+                            );
                             let _ = sub.append(&it);
                             Handle::Plain(it)
                         }
@@ -325,6 +342,7 @@ impl NativeMenu {
     /// Per frame: run chosen items, then sync labels / enabled / checked and the text-focus
     /// accelerators with the app state.
     pub fn update(&mut self, app: &mut LightcraftApp, ctx: &egui::Context) {
+        lightcraft_ui_egui::i18n::set_language(app.ui.language);
         while let Ok(key) = self.rx.try_recv() {
             if key == QUIT {
                 ctx.send_viewport_cmd(egui::ViewportCommand::Close);
@@ -352,8 +370,8 @@ impl NativeMenu {
                         let Some(it) = items.get_mut(&MenuNode::key(id, params)) else { continue };
                         if it.label != *label {
                             match &it.handle {
-                                Handle::Plain(h) => h.set_text(label_text(label)),
-                                Handle::Check(h) => h.set_text(label_text(label)),
+                                Handle::Plain(h) => h.set_text(lightcraft_ui_egui::menubar::display_item_label(id, params, label).replace('&', "&&")),
+                                Handle::Check(h) => h.set_text(lightcraft_ui_egui::menubar::display_item_label(id, params, label).replace('&', "&&")),
                             }
                             it.label = label.clone();
                         }
@@ -401,6 +419,27 @@ impl NativeMenu {
 mod tests {
     use super::*;
 
+    /// The menu model's titles stay English, so only the language can tell the native menu to
+    /// rebuild its titles (and the macOS app menu): every language switch — also between two CJK
+    /// languages — must change the structure key.
+    #[test]
+    fn switching_language_rebuilds_native_menu_structure() {
+        use lightcraft_ui_egui::i18n::{Locale, set_language};
+        let app = LightcraftApp::new(lightcraft_engine::Session::with_demo(), Default::default());
+        set_language(Locale::En);
+        let bar = menu_bar(&app);
+        let mut seen = std::collections::BTreeSet::new();
+        for language in Locale::ALL {
+            set_language(*language);
+            assert!(seen.insert(structure_of(&bar)), "{language:?} shares another language's menu structure key");
+        }
+        set_language(Locale::ZhHant);
+        assert_eq!(label_text("File"), "檔案");
+        assert_eq!(label_text("Settings…"), "設定…");
+        assert_eq!(label_text("Quit LightCraft"), "結束 LightCraft");
+        set_language(Locale::En);
+    }
+
     #[test]
     fn shortcuts_map_to_accelerators() {
         assert_eq!(accelerator("Cmd+Shift+Z"), Some(Accelerator::new(Modifiers::META | Modifiers::SHIFT, Code::KeyZ)));

assets/ATTRIBUTION.md

@@ -9,9 +9,8 @@ covers a whole directory), or if a licence file referenced in the Licence column
 | Path | Asset | Creator | Source | Licence | Added | Modifications |
 |---|---|---|---|---|---|---|
 | `assets/fonts/Inter-*.ttf` (Regular, Medium, SemiBold) | Inter | Rasmus Andersson | https://github.com/rsms/inter | SIL Open Font License 1.1 (`assets/fonts/OFL-Inter.txt`) | 2026-09-30 | none |
-| `assets/fonts/BIZUDMincho-Regular.ttf` | BIZ UDMincho Regular | The BIZ UDMincho Project Authors (Morisawa Inc., design TypeBank Co., Ltd.) | https://github.com/google/fonts/tree/63833b7d10bb1f86a8f0b91cba2d3ae1f68d1aa3/ofl/bizudmincho | OFL-1.1 (`assets/fonts/OFL-BIZUDMincho.txt`) | 2026-10-05 | none |
-| `assets/fonts/OFL-BIZUDMincho.txt` | BIZ UDMincho licence | The BIZ UDMincho Project Authors | https://github.com/google/fonts/blob/63833b7d10bb1f86a8f0b91cba2d3ae1f68d1aa3/ofl/bizudmincho/OFL.txt | OFL-1.1 | 2026-10-05 | none |
 | `assets/app-icon/` (`lightcraft.svg` and the PNG/ICNS/ICO/SVG files derived from it) | LightCraft app icon (lynx) | LightCraft project owner (drawn in ArtCraft) | original work (vectorised from the owner's drawing; see `assets/app-icon/README.md`) | MIT OR Apache-2.0 (`assets/app-icon/LICENSE.txt`) | 2026-10-02 | vectorised to SVG; rendered to PNG/ICNS/ICO by `packaging/icons.sh` |
+| `assets/camera-profiles/*.json` | Camera colour profiles (matrix + hue/saturation/value table), built into LightCraft | ILCE-7M4: Harald Hoyer | original work: fitted by `lightcraft-cli calibrate` to the contributor's own raw photos and their in-camera JPEGs (597 ILCE-7M4 photos, 2026); aggregate colour statistics only, no image content; no Adobe or third-party profile data | MIT OR Apache-2.0 | 2026-10-07 | none |
 | `crates/scenes/` (generated images) | Procedural demo photographs | LightCraft contributors | original work (generated at runtime, no source imagery) | MIT OR Apache-2.0 | 2026-09-30 | n/a |
 | `crates/ui-egui/src/icons.rs` | UI icons drawn as vector paths in code | LightCraft contributors | original work | MIT OR Apache-2.0 | 2026-09-30 | n/a |
 | `docs/images/*-tetons.jpg`, `docs/images/grid-pd.jpg` (screenshots containing it) | "The Tetons and the Snake River" | Ansel Adams (1942), U.S. National Archives | https://commons.wikimedia.org/wiki/File:Adams_The_Tetons_and_the_Snake_River.jpg | Public domain (U.S. federal government work) | 2026-09-30 | developed in LightCraft; shown inside app screenshots |
@@ -20,7 +19,12 @@ covers a whole directory), or if a licence file referenced in the Licence column
 | `docs/images/*-blue-marble.jpg`, `docs/images/grid-pd.jpg` | "The Blue Marble" (AS17-148-22727) | NASA, Apollo 17 crew (1972) | https://commons.wikimedia.org/wiki/File:The_Earth_seen_from_Apollo_17.jpg | Public domain (NASA) | 2026-09-30 | developed in LightCraft; shown inside app screenshots |
 | `docs/images/*.jpg` (UI) | LightCraft application screenshots | LightCraft contributors | original work (captured with `docs/showcase/`) | MIT OR Apache-2.0 | 2026-09-30 | n/a |
 | `docs/brand/` (artcraft-logo and artcraft-mark, SVG and PNG) | ArtCraft wordmark and mark | ArtCraft Team | original work (https://getartcraft.com/) | ArtCraft trademark, see `docs/brand/LICENSE-brand.txt` (not open source) | 2026-10-01 | none |
+| craft-fonts: optional build input, not files in this repository | BIZ UDPGothic (Regular, Bold), BIZ UDMincho Regular, Shippori Mincho Regular | Morisawa Inc. / The BIZ UDGothic and BIZ UDMincho Project Authors; The Shippori Mincho Project Authors (per craft-fonts' attribution) | https://github.com/storytold/craft-fonts/blob/main/ATTRIBUTION.md | SIL Open Font License 1.1 (each font's OFL.txt in craft-fonts; release packages ship it as OFL-<family>.txt) | 2026-10-06 | none; embedded only in builds made with `CRAFT_FONTS_DIR` (all official releases); the web (wasm32) build embeds BIZ UDPGothic Regular only |
 
 Notes
 - Fonts authored or published by Adobe (Source Sans/Serif/Code, Source Han, …) are not used, even though some are
   OFL-licensed: the asset rule excludes anything from Adobe. Source Sans 3 was removed on 2026-09-30 and replaced by Inter.
+- Japanese fonts (BIZ UDPGothic, BIZ UDMincho, Shippori Mincho) are not in this repository. They live in
+  [storytold/craft-fonts](https://github.com/storytold/craft-fonts), with their licences and attribution in its
+  `ATTRIBUTION.md`, and are embedded only in builds made with the optional `CRAFT_FONTS_DIR` build input (all official
+  releases). Never commit font files here; add new fonts to craft-fonts (craftrules `standards/fonts.md`).

assets/camera-profiles/ILCE-7M4.json

@@ -0,0 +1 @@
+{"version":1,"model":"ILCE-7M4","files":597,"samples":2182876,"matrix":[[1.06975,-0.0709886,-0.000770444],[-0.0169822,1.08012,-0.0651276],[-0.114835,-0.601525,1.74804]],"hue_sat":{"hue_divisions":72,"sat_divisions":5,"val_divisions":5,"data":[[0.0,1.0,1.0],[-0.819008,1.14375,1.0],[-6.07446,1.10974,1.0],[-4.0478,1.04285,1.0],[-0.546764,1.00329,1.0],[0.0,1.0,1.0],[-1.0412,1.10597,1.0],[-7.22645,1.05878,1.0],[-7.30635,0.989387,1.0],[-5.18589,0.974522,1.0],[0.0,1.0,1.0],[-1.02364,1.06303,1.0],[-6.94669,1.01579,1.0],[-7.47614,0.955435,1.0],[-7.02579,0.940854,1.0],[0.0,1.0,1.0],[-0.29852,1.04349,1.0],[-6.37202,1.00021,1.0],[-7.52098,0.935457,1.0],[-7.45702,0.922239,1.0],[0.0,1.0,1.0],[0.367464,1.03266,1.0],[-4.96951,0.996822,1.0],[-7.41706,0.948709,1.0],[-8.04735,0.91672,1.0],[0.0,1.0,1.0],[0.0388419,1.02587,1.0],[-4.47266,1.01282,1.0],[-7.26834,0.987279,1.0],[-9.02713,0.921453,1.0],[0.0,1.0,1.0],[-0.297476,1.02333,1.0],[-4.6323,1.00993,1.0],[-8.57248,0.962973,1.0],[-12.2375,0.872088,1.0],[0.0,1.0,1.0],[-0.785867,1.02786,1.0],[-4.73124,1.00876,1.0],[-9.09856,0.955343,1.0],[-12.4324,0.875472,1.0],[0.0,1.0,1.0],[-0.444072,1.03863,1.0],[-3.94773,1.01784,1.0],[-7.97996,0.975996,1.0],[-10.673,0.917401,1.0],[0.0,1.0,1.0],[1.22651,1.0559,1.0],[-1.89459,1.02934,1.0],[-5.54545,0.993046,1.0],[-8.48877,0.941628,1.0],[0.0,1.0,1.0],[3.24516,1.08292,1.0],[1.20522,1.0577,1.0],[-0.826224,1.01668,1.0],[-3.71884,0.946733,1.0],[0.0,1.0,1.0],[4.68802,1.12039,1.0],[3.23147,1.08619,1.0],[1.84476,1.04,1.0],[0.0970375,0.962298,1.0],[0.0,1.0,1.0],[5.36041,1.16313,1.0],[4.5937,1.10933,1.0],[3.83314,1.05056,1.0],[3.122,0.959876,1.0],[0.0,1.0,1.0],[5.22222,1.17824,1.0],[5.09129,1.1142,1.0],[4.99294,1.04813,1.0],[5.01485,0.957528,1.0],[0.0,1.0,1.0],[4.34382,1.18446,1.0],[4.9457,1.11351,1.0],[5.56715,1.04462,1.0],[6.27579,0.961892,1.0],[0.0,1.0,1.0],[3.5428,1.18985,1.0],[4.9116,1.11394,1.0],[6.11507,1.04098,1.0],[7.03638,0.964331,1.0],[0.0,1.0,1.0],[2.92641,1.20663,1.0],[4.57132,1.1281,1.0],[5.96964,1.04895,1.0],[6.98579,0.96261,1.0],[0.0,1.0,1.0],[2.07123,1.23257,1.0],[3.51736,1.15454,1.0],[4.85051,1.06995,1.0],[5.97805,0.971597,1.0],[0.0,1.0,1.0],[0.869122,1.26762,1.0],[2.22009,1.19021,1.0],[3.54297,1.10536,1.0],[4.31783,1.00254,1.0],[0.0,1.0,1.0],[-0.409355,1.31042,1.0],[0.778039,1.23845,1.0],[1.87845,1.15455,1.0],[1.53759,1.02961,1.0],[0.0,1.0,1.0],[-1.82067,1.35265,1.0],[-0.910751,1.28551,1.0],[-0.100378,1.18585,1.0],[0.0425375,1.01463,1.0],[0.0,1.0,1.0],[-3.26659,1.391,1.0],[-2.50117,1.33263,1.0],[-1.55789,1.18102,1.0],[-0.0853484,1.00594,1.0],[0.0,1.0,1.0],[-4.92446,1.43632,1.0],[-3.92066,1.35798,1.0],[-1.66274,1.11605,1.0],[-0.0358972,1.00178,1.0],[0.0,1.0,1.0],[-5.82474,1.46137,1.0],[-4.22466,1.34716,1.0],[-0.64525,1.04813,1.0],[-0.00357121,1.00023,1.0],[0.0,1.0,1.0],[-7.0672,1.47242,1.0],[-5.38667,1.32663,1.0],[-0.553542,1.02668,1.0],[-0.00188478,1.00008,1.0],[0.0,1.0,1.0],[-8.37522,1.43136,1.0],[-6.13631,1.28174,1.0],[-0.515332,1.01808,1.0],[-0.0015762,1.00005,1.0],[0.0,1.0,1.0],[-10.5196,1.39935,1.0],[-7.49316,1.24442,1.0],[-0.517621,1.01282,1.0],[-0.001445,1.00003,1.0],[0.0,1.0,1.0],[-10.5952,1.3534,1.0],[-7.81548,1.20414,1.0],[-0.63473,1.0111,1.0],[-0.00208267,1.00003,1.0],[0.0,1.0,1.0],[-10.879,1.32051,1.0],[-8.3374,1.18517,1.0],[-0.91817,1.01139,1.0],[-0.00474972,1.00003,1.0],[0.0,1.0,1.0],[-11.8094,1.29525,1.0],[-9.18818,1.17522,1.0],[-0.968552,1.01157,1.0],[-0.00411555,1.00003,1.0],[0.0,1.0,1.0],[-12.2038,1.27777,1.0],[-8.97374,1.15856,1.0],[-0.751018,1.00872,1.0],[-0.00250012,1.00002,1.0],[0.0,1.0,1.0],[-12.0564,1.2709,1.0],[-8.38288,1.15926,1.0],[-0.643806,1.00878,1.0],[-0.00202184,1.00002,1.0],[0.0,1.0,1.0],[-12.8403,1.25618,1.0],[-8.85664,1.14517,1.0],[-0.646111,1.00756,1.0],[-0.00195373,1.00001,1.0],[0.0,1.0,1.0],[-13.2604,1.25094,1.0],[-8.74013,1.11989,1.0],[-0.556009,1.00457,1.0],[-0.00173404,1.00001,1.0],[0.0,1.0,1.0],[-13.3939,1.24388,1.0],[-8.23916,1.11659,1.0],[-0.376536,1.00355,1.0],[-0.000916476,1.00001,1.0],[0.0,1.0,1.0],[-13.6578,1.24212,1.0],[-7.97883,1.11035,1.0],[-0.409859,1.00287,1.0],[-0.0018203,1.0,1.0],[0.0,1.0,1.0],[-15.7225,1.22414,1.0],[-10.2345,1.10217,1.0],[-0.968177,1.00427,1.0],[-0.00650675,1.00001,1.0],[0.0,1.0,1.0],[-16.1557,1.16423,1.0],[-12.721,1.06603,1.0],[-2.02337,1.00334,1.0],[-0.0134173,1.00001,1.0],[0.0,1.0,1.0],[-17.253,1.09714,1.0],[-15.785,1.02184,1.0],[-4.02264,0.996649,1.0],[-0.0279292,0.999956,1.0],[0.0,1.0,1.0],[-17.6206,1.04331,1.0],[-16.2039,0.99401,1.0],[-4.09728,0.990246,1.0],[-0.0269801,0.999896,1.0],[0.0,1.0,1.0],[-17.2302,0.987569,1.0],[-15.1656,0.964114,1.0],[-3.21398,0.983725,1.0],[-0.0202065,0.999807,1.0],[0.0,1.0,1.0],[-16.2184,0.943678,1.0],[-13.4633,0.938141,1.0],[-3.40639,0.971571,1.0],[-0.00923182,0.999563,1.0],[0.0,1.0,1.0],[-14.5653,0.909699,1.0],[-11.6873,0.915733,1.0],[-5.4654,0.942337,1.0],[-0.124331,0.998194,1.0],[0.0,1.0,1.0],[-11.5122,0.906891,1.0],[-9.31547,0.923874,1.0],[-6.12222,0.939832,1.0],[-0.337538,0.995963,1.0],[0.0,1.0,1.0],[-7.77619,0.92294,1.0]Line truncated

assets/fonts/OFL-BIZUDMincho.txt

@@ -1,93 +0,0 @@
-Copyright 2022 The BIZ UDMincho Project Authors (https://github.com/googlefonts/morisawa-biz-ud-mincho)
-
-This Font Software is licensed under the SIL Open Font License, Version 1.1.
-This license is copied below, and is also available with a FAQ at:
-https://scripts.sil.org/OFL
-
-
------------------------------------------------------------
-SIL OPEN FONT LICENSE Version 1.1 - 26 February 2007
------------------------------------------------------------
-
-PREAMBLE
-The goals of the Open Font License (OFL) are to stimulate worldwide
-development of collaborative font projects, to support the font creation
-efforts of academic and linguistic communities, and to provide a free and
-open framework in which fonts may be shared and improved in partnership
-with others.
-
-The OFL allows the licensed fonts to be used, studied, modified and
-redistributed freely as long as they are not sold by themselves. The
-fonts, including any derivative works, can be bundled, embedded, 
-redistributed and/or sold with any software provided that any reserved
-names are not used by derivative works. The fonts and derivatives,
-however, cannot be released under any other type of license. The
-requirement for fonts to remain under this license does not apply
-to any document created using the fonts or their derivatives.
-
-DEFINITIONS
-"Font Software" refers to the set of files released by the Copyright
-Holder(s) under this license and clearly marked as such. This may
-include source files, build scripts and documentation.
-
-"Reserved Font Name" refers to any names specified as such after the
-copyright statement(s).
-
-"Original Version" refers to the collection of Font Software components as
-distributed by the Copyright Holder(s).
-
-"Modified Version" refers to any derivative made by adding to, deleting,
-or substituting -- in part or in whole -- any of the components of the
-Original Version, by changing formats or by porting the Font Software to a
-new environment.
-
-"Author" refers to any designer, engineer, programmer, technical
-writer or other person who contributed to the Font Software.
-
-PERMISSION & CONDITIONS
-Permission is hereby granted, free of charge, to any person obtaining
-a copy of the Font Software, to use, study, copy, merge, embed, modify,
-redistribute, and sell modified and unmodified copies of the Font
-Software, subject to the following conditions:
-
-1) Neither the Font Software nor any of its individual components,
-in Original or Modified Versions, may be sold by itself.
-
-2) Original or Modified Versions of the Font Software may be bundled,
-redistributed and/or sold with any software, provided that each copy
-contains the above copyright notice and this license. These can be
-included either as stand-alone text files, human-readable headers or
-in the appropriate machine-readable metadata fields within text or
-binary files as long as those fields can be easily viewed by the user.
-
-3) No Modified Version of the Font Software may use the Reserved Font
-Name(s) unless explicit written permission is granted by the corresponding
-Copyright Holder. This restriction only applies to the primary font name as
-presented to the users.
-
-4) The name(s) of the Copyright Holder(s) or the Author(s) of the Font
-Software shall not be used to promote, endorse or advertise any
-Modified Version, except to acknowledge the contribution(s) of the
-Copyright Holder(s) and the Author(s) or with their explicit written
-permission.
-
-5) The Font Software, modified or unmodified, in part or in whole,
-must be distributed entirely under this license, and must not be
-distributed under any other license. The requirement for fonts to
-remain under this license does not apply to any document created
-using the Font Software.
-
-TERMINATION
-This license becomes null and void if any of the above conditions are
-not met.
-
-DISCLAIMER
-THE FONT SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
-EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTIES OF
-MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT
-OF COPYRIGHT, PATENT, TRADEMARK, OR OTHER RIGHT. IN NO EVENT SHALL THE
-COPYRIGHT HOLDER BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
-INCLUDING ANY GENERAL, SPECIAL, INDIRECT, INCIDENTAL, OR CONSEQUENTIAL
-DAMAGES, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
-FROM, OUT OF THE USE OR INABILITY TO USE THE FONT SOFTWARE OR FROM
-OTHER DEALINGS IN THE FONT SOFTWARE.

crates/catalog/Cargo.toml

@@ -10,6 +10,7 @@ workspace = true
 
 [dependencies]
 lightcraft-develop = { workspace = true }
+lightcraft-meta = { workspace = true }
 serde = { workspace = true }
 serde_json = { workspace = true }
 thiserror = { workspace = true }

crates/catalog/src/lib.rs

@@ -35,7 +35,7 @@ use lightcraft_develop::DevelopSettings;
 pub use local::{DEFAULT_FORGET_DAYS, ForgetPlan, folder_of};
 pub use lock::{LibraryLock, LockError, LockOwner};
 pub use model::*;
-pub use query::{DateGroup, Filter, RatingOp, Sort, SortKey};
+pub use query::{DateGroup, Filter, Person, RatingOp, Sort, SortKey};
 pub use rules::{Match, Rule, RuleSet};
 use serde::{Deserialize, Serialize};
 pub use store::{FsStore, MemStore, Store};

crates/catalog/src/model.rs

@@ -183,6 +183,11 @@ pub struct Meta {
     pub copyright_url: String,
     pub creator: String,
     pub keywords: Vec<String>,
+    /// Face/pet/focus regions read from XMP (MWG-RS), on the upright (EXIF-oriented) photo.
+    /// Removing or resizing one edits the catalog only; LightCraft never writes regions to XMP.
+    /// Left out of the catalog JSON when empty (most photos), so older catalogs read unchanged.
+    #[serde(default, skip_serializing_if = "Vec::is_empty")]
+    pub regions: Vec<lightcraft_meta::Region>,
 }
 
 #[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
@@ -331,6 +336,12 @@ impl Photo {
     pub fn develops_raw(&self) -> bool {
         self.kind == MediaKind::Raw && self.preview_only.is_none()
     }
+    /// The current ARW and NEF readers have vendor WB multipliers but no measured camera
+    /// illuminant. Use adjustments relative to the camera's as-shot look, as for rendered
+    /// photographs (the engine's `camera_preview::file_local_look` covers the same formats).
+    pub fn relative_wb(&self) -> bool {
+        self.develops_raw() && ["ARW", "NEF", "NRW"].iter().any(|f| self.format.eq_ignore_ascii_case(f))
+    }
     /// The develop settings import gave this photo: [`Photo::camera_defaults`], or the user's
     /// default preset applied on top of them ([`Photo::import_look`]).
     pub fn import_defaults(&self) -> DevelopSettings {
@@ -342,7 +353,8 @@ impl Photo {
     /// The built-in defaults for this photo, before any user default preset: raws start from
     /// their as-shot white balance; embedded lens corrections on when the file has them.
     pub fn camera_defaults(&self) -> DevelopSettings {
-        let mut d = match self.as_shot_wb {
+        let wb = if self.relative_wb() { Some((6500.0, 0.0)) } else { self.as_shot_wb };
+        let mut d = match wb {
             Some((t, tint)) => DevelopSettings::for_raw(t, tint),
             None => DevelopSettings::default(),
         };
@@ -415,4 +427,19 @@ mod edited_tests {
         p.develop = Arc::new(DevelopSettings::default());
         assert!(!p.is_edited(), "a full reset is unedited too");
     }
+
+    #[test]
+    fn sony_and_nikon_raws_use_relative_white_balance() {
+        for (name, format, relative) in [("a.arw", "ARW", true), ("a.nef", "NEF", true), ("a.nrw", "nrw", true), ("a.dng", "DNG", false)] {
+            let mut p = Photo::new(PhotoId(1), Source::Demo { scene: 0 }, name, format, 10, 10, "2026-10-01T00:00:00");
+            p.kind = MediaKind::Raw;
+            p.as_shot_wb = Some((5200.0, 4.0));
+            assert_eq!(p.relative_wb(), relative, "{format}");
+            let wb = p.camera_defaults().wb;
+            assert_eq!((wb.temp, wb.tint), if relative { (6500.0, 0.0) } else { (5200.0, 4.0) }, "{format}");
+            // shown from the embedded preview: a rendered image, not a relative-WB raw
+            p.preview_only = Some("unsupported".into());
+            assert!(!p.relative_wb());
+        }
+    }
 }

crates/catalog/src/query.rs

@@ -39,6 +39,8 @@ pub struct Filter {
     pub date: Option<String>,
     /// A keyword; hierarchical keywords match their children too (`travel` finds `travel|italy`).
     pub keyword: Option<String>,
+    /// A person: photos with a named face region of this name (case-insensitive), as read from XMP.
+    pub person: Option<String>,
     pub camera: Option<String>,
     /// Lens (case-insensitive substring).
     pub lens: Option<String>,
@@ -113,6 +115,7 @@ fn token_matches(p: &Photo, tok: &str) -> bool {
             "camera" => p.meta.camera.to_lowercase().contains(val),
             "lens" => p.meta.lens.to_lowercase().contains(val),
             "keyword" | "kw" => p.meta.keywords.iter().any(|k| crate::keywords::is_under(k, val)),
+            "person" | "who" => has_person(p, val),
             "type" | "kind" => format!("{:?}", p.kind).eq_ignore_ascii_case(val),
             "edited" => (val == "true" || val == "yes") == p.is_edited(),
             "date" => p.date().starts_with(val),
@@ -125,6 +128,12 @@ fn token_matches(p: &Photo, tok: &str) -> bool {
     hay.iter().any(|h| h.to_lowercase().contains(&t)) || p.meta.keywords.iter().any(|k| k.to_lowercase().contains(&t))
 }
 
+/// Whether `p` has a named face region called `name` (case-insensitive).
+fn has_person(p: &Photo, name: &str) -> bool {
+    let name = name.trim().to_lowercase();
+    p.meta.regions.iter().any(|r| r.kind == lightcraft_meta::RegionKind::Face && r.name.as_deref().is_some_and(|n| n.to_lowercase() == name))
+}
+
 impl Filter {
     /// Human-readable summary of the active rules (smart album tooltips, `album.list`).
     pub fn describe(&self) -> String {
@@ -152,9 +161,14 @@ impl Filter {
         if let Some(e) = self.edited {
             v.push(if e { "edited".into() } else { "unedited".into() });
         }
-        for (name, val) in
-            [("keyword", &self.keyword), ("camera", &self.camera), ("lens", &self.lens), ("date", &self.date), ("imported", &self.imported)]
-        {
+        for (name, val) in [
+            ("keyword", &self.keyword),
+            ("person", &self.person),
+            ("camera", &self.camera),
+            ("lens", &self.lens),
+            ("date", &self.date),
+            ("imported", &self.imported),
+        ] {
             if let Some(x) = val {
                 v.push(format!("{name} {x}"));
             }
@@ -267,6 +281,11 @@ impl Filter {
         {
             return false;
         }
+        if let Some(n) = &self.person
+            && !has_person(p, n)
+        {
+            return false;
+        }
         if let Some(c) = &self.camera
             && !p.meta.camera.eq_ignore_ascii_case(c)
         {
@@ -330,6 +349,54 @@ impl Catalog {
         }
         m.into_iter().collect()
     }
+
+    /// The people named on faces in the library (MWG regions read from XMP): how many photos each
+    /// appears in and the photo showing their largest face (for a card's picture). Most photos first,
+    /// then by name. Names that differ only in case are one person, shown as first seen; a person
+    /// twice in one photo counts once.
+    pub fn people(&self) -> Vec<Person> {
+        self.people_in(&Filter::default())
+    }
+
+    /// [`Self::people`] among the photos `filter` lets through (its `person` is ignored): what the
+    /// People view offers while other filters (a date, a rating, an album…) are active, so picking
+    /// a person never ends in an empty grid.
+    pub fn people_in(&self, filter: &Filter) -> Vec<Person> {
+        let filter = Filter { person: None, ..filter.clone() };
+        let mut m: std::collections::HashMap<String, (Person, f64)> = Default::default();
+        for p in self.photos().filter(|p| filter.matches(p, self)) {
+            let mut seen: Vec<String> = Vec::new();
+            for r in p.meta.regions.iter().filter(|r| r.kind == lightcraft_meta::RegionKind::Face) {
+                let Some(name) = r.name.as_deref().map(str::trim).filter(|n| !n.is_empty()) else { continue };
+                let key = name.to_lowercase();
+                // the face's size in pixels of the photo
+                let area = (r.rect.x1 - r.rect.x0) * (r.rect.y1 - r.rect.y0) * p.width as f64 * p.height as f64;
+                let (person, best) =
+                    m.entry(key.clone()).or_insert_with(|| (Person { name: name.to_string(), count: 0, photo: p.id, face: r.rect }, area));
+                if !seen.contains(&key) {
+                    person.count += 1;
+                    seen.push(key);
+                }
+                if area > *best || (area == *best && p.id < person.photo) {
+                    (person.photo, person.face, *best) = (p.id, r.rect, area);
+                }
+            }
+        }
+        let mut v: Vec<Person> = m.into_values().map(|(p, _)| p).collect();
+        v.sort_by(|a, b| b.count.cmp(&a.count).then_with(|| a.name.to_lowercase().cmp(&b.name.to_lowercase())));
+        v
+    }
+}
+
+/// A person named on faces in the library ([`Catalog::people`]).
+#[derive(Clone, Debug, PartialEq)]
+pub struct Person {
+    pub name: String,
+    /// Photos they appear in.
+    pub count: usize,
+    /// The photo with their largest face, and that face (normalized, in the photo's upright frame).
+    pub photo: PhotoId,
+    pub face: lightcraft_meta::Rect,
 }
 
 #[derive(Clone, Debug, PartialEq, Serialize)]

crates/catalog/src/safe_file.rs

@@ -1,11 +1,23 @@
 //! Crash-safe writes of user-visible files: exports, renders, DNG conversions, smart previews and
 //! XMP sidecars all go through here (the catalog's own files use [`crate::store::FsStore`]).
 //!
+//! **Write policy** (issue #134): what can't be recreated — originals, XMP sidecars, the catalog,
+//! settings, DNGs that replace raws, smart previews (the only stand-in while an original is
+//! offline), an edit copy that becomes a library photo — is written **durably**: synced to disk
+//! before it counts as written. What can always be made again from the originals — exports,
+//! renders, screenshots, merge previews — is written **atomically** only: a half-written file
+//! never replaces a good one, but there is no per-file sync (on a USB drive or a NAS that sync
+//! dominates a large export).
+//!
 //! - [`write_atomic`] replaces a file so that after a crash, a full disk or an unplugged drive
 //!   either the old or the complete new content is there — never a truncated mix. The content
 //!   goes to a new temp file in the same folder (unique name, `create_new`), is synced to disk and
 //!   renamed over the target; then the folder is synced (POSIX). Any failure removes the temp
 //!   file and leaves the target as it was.
+//! - [`write_atomic_nosync`] is the same temp file + rename without the two syncs, for
+//!   recreatable outputs only: a failed write still removes the temp file and leaves the target as
+//!   it was, but after a power cut the new file may be lost (on some file systems left empty) —
+//!   it is then simply exported again.
 //! - [`write_new`] / [`write_new_unique`] write a file that must not exist yet: the same temp file
 //!   and sync, plus a read-back check, and the file then appears under its final name **without
 //!   replacing anything** (a hard link, which fails on a taken name; a check-then-rename where the
@@ -21,6 +33,19 @@ use std::sync::atomic::{AtomicU64, Ordering};
 
 thread_local! {
     static FAIL_AFTER: Cell<Option<u64>> = const { Cell::new(None) };
+    static SYNCS: Cell<u64> = const { Cell::new(0) };
+}
+
+/// How many file and folder syncs this module made **on the calling thread** (for tests: a
+/// durable write path syncs, a recreatable output doesn't).
+#[doc(hidden)]
+pub fn syncs_on_this_thread() -> u64 {
+    SYNCS.with(Cell::get)
+}
+
+fn sync_file(f: &File) -> io::Result<()> {
+    SYNCS.with(|c| c.set(c.get() + 1));
+    f.sync_all()
 }
 
 /// Fault injection for tests (in any crate): while the returned guard lives, every write made by
@@ -78,7 +103,7 @@ fn parent_of(path: &Path) -> &Path {
 /// where NTFS journals the rename itself, so errors are ignored.
 pub fn sync_dir(dir: &Path) {
     if let Ok(d) = File::open(dir) {
-        let _ = d.sync_all();
+        let _ = sync_file(&d);
     }
 }
 
@@ -100,9 +125,9 @@ fn create_temp(path: &Path) -> io::Result<(PathBuf, File)> {
     Err(io::Error::new(io::ErrorKind::AlreadyExists, format!("no free temp file name in {}", dir.display())))
 }
 
-/// Write a temp file next to `path` with what `fill` writes, synced to disk. On failure the temp
-/// file is removed. Returns its path and length.
-fn write_temp(path: &Path, fill: &mut dyn FnMut(&mut dyn Write) -> io::Result<()>) -> io::Result<(PathBuf, u64)> {
+/// Write a temp file next to `path` with what `fill` writes, synced to disk when `sync`. On
+/// failure the temp file is removed. Returns its path and length.
+fn write_temp(path: &Path, sync: bool, fill: &mut dyn FnMut(&mut dyn Write) -> io::Result<()>) -> io::Result<(PathBuf, u64)> {
     let (tmp, file) = create_temp(path)?;
     let r = (|| {
         let limit = FAIL_AFTER.with(Cell::get);
@@ -111,7 +136,9 @@ fn write_temp(path: &Path, fill: &mut dyn FnMut(&mut dyn Write) -> io::Result<()
         w.flush()?;
         let n = w.n;
         let f = w.inner.into_inner().map_err(|e| e.into_error())?;
-        f.sync_all()?;
+        if sync {
+            sync_file(&f)?;
+        }
         Ok(n)
     })();
     match r {
@@ -132,12 +159,26 @@ pub fn write_atomic(path: &Path, data: &[u8]) -> io::Result<()> {
 /// [`write_atomic`] with streamed content: `fill` writes it (an error aborts and leaves the old
 /// file). Returns the length written.
 pub fn write_atomic_with(path: &Path, fill: &mut dyn FnMut(&mut dyn Write) -> io::Result<()>) -> io::Result<u64> {
-    let (tmp, n) = write_temp(path, fill)?;
+    replace_with(path, true, fill)
+}
+
+/// Replace (or create) `path` with `data` atomically but **without syncing** it to disk — only for
+/// outputs that can always be recreated (exports, renders, screenshots); see the module docs.
+/// Anything that can't be made again goes through [`write_atomic`].
+pub fn write_atomic_nosync(path: &Path, data: &[u8]) -> io::Result<()> {
+    replace_with(path, false, &mut |w| w.write_all(data)).map(|_| ())
+}
+
+/// Temp file (synced when `sync`) renamed over `path`, then the folder synced when `sync`.
+fn replace_with(path: &Path, sync: bool, fill: &mut dyn FnMut(&mut dyn Write) -> io::Result<()>) -> io::Result<u64> {
+    let (tmp, n) = write_temp(path, sync, fill)?;
     if let Err(e) = fs::rename(&tmp, path) {
         let _ = fs::remove_file(&tmp);
         return Err(e);
     }
-    sync_dir(parent_of(path));
+    if sync {
+        sync_dir(parent_of(path));
+    }
     Ok(n)
 }
 
@@ -155,8 +196,11 @@ pub fn write_new_unique(candidates: &mut dyn Iterator<Item = PathBuf>, data: &[u
     let Some(first) = candidates.peek().cloned() else {
         return Err(io::Error::new(io::ErrorKind::InvalidInput, "no file name to write"));
     };
-    let (tmp, _) = write_temp(&first, &mut |w| w.write_all(data))?;
+    let (tmp, _) = write_temp(&first, true, &mut |w| w.write_all(data))?;
     let r = (|| {
+        // Kept (issue #134 point 4): these files replace raws (Convert / Copy as DNG) or become
+        // library photos (merges). On a local disk the read usually comes from the cache, but on a
+        // network volume it can go back to the server, and next to encoding a DNG it costs little.
         if !same_content(&tmp, data)? {
             return Err(io::Error::other("the written file reads back different (failing drive or connection?)"));
         }
@@ -287,6 +331,33 @@ mod tests {
         let _ = fs::remove_dir_all(&d);
     }
 
+    #[test]
+    fn recreatable_outputs_are_atomic_without_a_sync() {
+        let d = temp("nosync");
+        let p = d.join("export.jpg");
+        let before = syncs_on_this_thread();
+        write_atomic_nosync(&p, b"one").unwrap();
+        write_atomic_nosync(&p, b"two two").unwrap();
+        assert_eq!(syncs_on_this_thread(), before, "no file or folder sync");
+        assert_eq!(fs::read(&p).unwrap(), b"two two");
+        assert_eq!(names(&d), vec!["export.jpg"], "no temp file left");
+        // still atomic: a failure part-way leaves the previous file and no temp file
+        {
+            let _f = fail_writes_after(3);
+            assert!(write_atomic_nosync(&p, &[9u8; 10_000]).is_err());
+        }
+        assert_eq!(fs::read(&p).unwrap(), b"two two");
+        assert_eq!(names(&d), vec!["export.jpg"]);
+        // the durable writers do sync (the file; the folder too where it can be opened)
+        let before = syncs_on_this_thread();
+        write_atomic(&p, b"three").unwrap();
+        let mid = syncs_on_this_thread();
+        assert!(mid > before);
+        write_new(&d.join("new.dng"), b"dng").unwrap();
+        assert!(syncs_on_this_thread() > mid);
+        let _ = fs::remove_dir_all(&d);
+    }
+
     #[test]
     fn new_files_never_replace_anything() {
         let d = temp("new");

crates/catalog/src/tests.rs

@@ -297,3 +297,86 @@ fn folder_identity_ignores_spelling() {
     assert!(folder_within("/a/b", "/"));
     assert!(folder_within("C:\\x", "c:\\"));
 }
+
+/// People come from named *face* regions: counted once per photo, case-insensitive, most photos
+/// first; pets and unnamed faces are not people; the `person` filter and `person:` token match.
+#[test]
+fn people_from_named_face_regions() {
+    use lightcraft_meta::{Rect, Region, RegionKind};
+    let region = |name: Option<&str>, kind: RegionKind| Region {
+        rect: Rect { x0: 0.4, y0: 0.4, x1: 0.6, y1: 0.6 },
+        kind,
+        name: name.map(str::to_string),
+        description: None,
+    };
+    let mut c = Catalog::new();
+    let mut add = |name: &str, regions: Vec<Region>| {
+        let id = c.alloc_photo_id();
+        let mut p = Photo::new(id, Source::Demo { scene: 1 }, name, "JPEG", 6000, 4000, "2026-09-30T10:00:00");
+        p.meta.regions = regions;
+        c.apply(Op::AddPhoto { photo: Box::new(p) }).unwrap();
+        id
+    };
+    let a = add(
+        "a.jpg",
+        vec![region(Some("Jane Doe"), RegionKind::Face), region(Some("jane doe"), RegionKind::Face), region(Some("Rex"), RegionKind::Pet)],
+    );
+    let b =
+        add("b.jpg", vec![region(Some("JANE DOE"), RegionKind::Face), region(Some("John Roe"), RegionKind::Face), region(None, RegionKind::Face)]);
+    let big = Rect { x0: 0.2, y0: 0.2, x1: 0.8, y1: 0.8 };
+    let d = add("d.jpg", vec![Region { rect: big, ..region(Some("John Roe"), RegionKind::Face) }]);
+    let e = add("e.jpg", vec![region(Some("Sam"), RegionKind::Face)]);
+    add("f.jpg", vec![]);
+    let people = c.people();
+    let summary: Vec<(&str, usize)> = people.iter().map(|p| (p.name.as_str(), p.count)).collect();
+    assert_eq!(summary, vec![("Jane Doe", 2), ("John Roe", 2), ("Sam", 1)], "once per photo, pets and unnamed faces left out");
+    // the picture is the person's largest face; ties go to the lower photo id
+    assert_eq!((people[0].photo, people[0].face), (a, Rect { x0: 0.4, y0: 0.4, x1: 0.6, y1: 0.6 }));
+    assert_eq!((people[1].photo, people[1].face), (d, big), "the larger face wins over an earlier, smaller one");
+
+    let q = |f: Filter| c.query(&f, &Sort::default());
+    assert_eq!(q(Filter { person: Some("jane doe".into()), ..Default::default() }).len(), 2);
+    let mut got = q(Filter { person: Some("John Roe".into()), ..Default::default() });
+    got.sort();
+    assert_eq!(got, vec![b, d]);
+    assert!(q(Filter { person: Some("Rex".into()), ..Default::default() }).is_empty(), "a pet is not a person");
+    assert_eq!(q(Filter { text: "person:SAM".into(), ..Default::default() }), vec![e], "the search token finds a person, any case");
+    assert!(q(Filter { person: Some("Jane Doe".into()), ..Default::default() }).contains(&a));
+
+    // other filters narrow who is offered (so picking a person never ends in an empty grid); the
+    // `person` filter itself does not
+    c.apply(Op::SetRating { id: b, rating: 3 }).unwrap();
+    let names = |f: Filter| c.people_in(&f).into_iter().map(|p| (p.name, p.count)).collect::<Vec<_>>();
+    let rated = Filter { rating: 1, ..Default::default() };
+    assert_eq!(
+        names(rated.clone()),
+        vec![("JANE DOE".to_string(), 1), ("John Roe".to_string(), 1)],
+        "only the rated photo's people, counted within it, spelled as first seen there"
+    );
+    assert_eq!(
+        names(Filter { person: Some("Sam".into()), ..rated }),
+        names(Filter { rating: 1, ..Default::default() }),
+        "the person filter is ignored"
+    );
+    assert_eq!(names(Filter { rating: 5, ..Default::default() }), vec![], "nobody in the filtered photos");
+}
+
+/// Most photos have no regions: the field is left out of the catalog JSON then, and a catalog written
+/// before regions existed (no `regions` key) reads with none.
+#[test]
+fn empty_regions_are_not_serialized_and_default_when_missing() {
+    let m = Meta { keywords: vec!["k".into()], ..Default::default() };
+    let v = serde_json::to_value(&m).unwrap();
+    assert!(v.get("regions").is_none(), "{v}");
+    let back: Meta = serde_json::from_value(v).unwrap();
+    assert!(back.regions.is_empty());
+    let mut with = m.clone();
+    with.regions.push(lightcraft_meta::Region {
+        rect: lightcraft_meta::Rect { x0: 0.1, y0: 0.1, x1: 0.2, y1: 0.2 },
+        kind: lightcraft_meta::RegionKind::Face,
+        name: Some("A".into()),
+        description: None,
+    });
+    let back: Meta = serde_json::from_str(&serde_json::to_string(&with).unwrap()).unwrap();
+    assert_eq!(back, with);
+}

crates/develop/Cargo.toml

@@ -13,6 +13,7 @@ lightcraft-geom = { workspace = true }
 lightcraft-color = { workspace = true }
 serde = { workspace = true }
 serde_json = { workspace = true }
+miniz_oxide = { workspace = true }
 
 [dev-dependencies]
 proptest = { workspace = true }

crates/develop/src/lib.rs

@@ -8,10 +8,12 @@
 
 pub mod controls;
 pub mod presets;
+pub mod segmask;
 pub mod settings;
 
 pub use controls::{CONTROLS, ControlSpec, Section, Track};
 pub use presets::{Preset, SettingsGroup, apply_partial, extract_groups};
+pub use segmask::SegMask;
 pub use settings::*;
 
 use serde_json::Value;

crates/develop/src/segmask.rs

@@ -0,0 +1,183 @@
+//! Model segmentations stored with a mask ([`SegMask`]), so rendering never needs the model.
+
+use serde::{Deserialize, Serialize};
+
+/// Logits are stored in steps of 1/`SCALE`, clamped to ±127/`SCALE` (≈ ±15.9: a sigmoid of
+/// 1 − 1.2e-7, i.e. fully in or out).
+const SCALE: f32 = 8.0;
+/// Largest grid a stored segmentation may claim (hostile input caps the allocation).
+pub const MAX_SIDE: usize = 1024;
+
+/// A segmentation computed by a model (SAM 3 in `lightcraft-segment`): `side × side` logits
+/// over the uncropped, oriented image stretched to a square (row `y`, column `x` covers
+/// normalized `((x + 0.5) / side, (y + 0.5) / side)`), quantized to `i8`, deflated and base64
+/// encoded. Coverage at a point is the sigmoid of the bilinearly sampled logit, so edges stay
+/// smooth at any output size.
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
+pub struct SegMask {
+    pub side: u32,
+    pub data: String,
+    /// The part of the image the grid covers, normalized `[x0, y0, x1, y1]` (`None` = all of
+    /// it). A zoomed-in pass over one object covers just its surroundings, at a higher
+    /// resolution than a pass over the whole photo.
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub rect: Option<[f64; 4]>,
+}
+
+impl SegMask {
+    /// From `side × side` logits over the whole image.
+    pub fn from_logits(side: usize, logits: &[f32]) -> SegMask {
+        let q: Vec<u8> = logits.iter().take(side * side).map(|l| ((l * SCALE).round().clamp(-127.0, 127.0) as i8) as u8).collect();
+        let z = miniz_oxide::deflate::compress_to_vec(&q, 8);
+        SegMask { side: side as u32, data: base64_encode(&z), rect: None }
+    }
+
+    /// From `side × side` logits over the part `rect` of the image.
+    pub fn from_logits_in(side: usize, logits: &[f32], rect: [f64; 4]) -> SegMask {
+        SegMask { rect: Some(rect), ..SegMask::from_logits(side, logits) }
+    }
+
+    /// The covered part, normalized (the whole image without a `rect`); `None` when damaged.
+    pub fn bounds(&self) -> Option<[f64; 4]> {
+        let r = self.rect.unwrap_or([0.0, 0.0, 1.0, 1.0]);
+        (r.iter().all(|v| v.is_finite()) && r[2] > r[0] && r[3] > r[1]).then_some(r)
+    }
+
+    /// The logits, or `None` when the data is damaged or claims an absurd size.
+    pub fn logits(&self) -> Option<Vec<f32>> {
+        let side = self.side as usize;
+        if side == 0 || side > MAX_SIDE {
+            return None;
+        }
+        let z = base64_decode(&self.data)?;
+        let q = miniz_oxide::inflate::decompress_to_vec_with_limit(&z, side * side).ok()?;
+        (q.len() == side * side).then(|| q.iter().map(|b| f32::from(*b as i8) / SCALE).collect())
+    }
+}
+
+/// Most zoomed-in detail patches one AI mask component keeps (the app makes one; each costs a
+/// decode per render, so a hostile document can't make rendering explode).
+pub const MAX_DETAIL: usize = 4;
+
+/// Deserialize a component's detail patches, keeping at most [`MAX_DETAIL`] (the rest are
+/// skipped without being decoded).
+pub(crate) fn de_detail<'de, D: serde::Deserializer<'de>>(d: D) -> Result<Vec<SegMask>, D::Error> {
+    struct Capped;
+    impl<'de> serde::de::Visitor<'de> for Capped {
+        type Value = Vec<SegMask>;
+        fn expecting(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+            f.write_str("a list of segmentations")
+        }
+        fn visit_seq<A: serde::de::SeqAccess<'de>>(self, mut seq: A) -> Result<Vec<SegMask>, A::Error> {
+            let mut out = Vec::new();
+            while out.len() < MAX_DETAIL {
+                match seq.next_element::<SegMask>()? {
+                    Some(m) => out.push(m),
+                    None => return Ok(out),
+                }
+            }
+            while seq.next_element::<serde::de::IgnoredAny>()?.is_some() {}
+            Ok(out)
+        }
+    }
+    d.deserialize_seq(Capped)
+}
+
+const B64: &[u8; 64] = b"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
+
+fn base64_encode(bytes: &[u8]) -> String {
+    let mut out = String::with_capacity(bytes.len().div_ceil(3) * 4);
+    for chunk in bytes.chunks(3) {
+        let b = [chunk.first().copied().unwrap_or(0), chunk.get(1).copied().unwrap_or(0), chunk.get(2).copied().unwrap_or(0)];
+        let n = (u32::from(b[0]) << 16) | (u32::from(b[1]) << 8) | u32::from(b[2]);
+        for i in 0..4 {
+            if i <= chunk.len() {
+                out.push(char::from(B64[((n >> (18 - 6 * i)) & 63) as usize]));
+            } else {
+                out.push('=');
+            }
+        }
+    }
+    out
+}
+
+fn base64_decode(s: &str) -> Option<Vec<u8>> {
+    let mut out = Vec::with_capacity(s.len() / 4 * 3);
+    let (mut acc, mut bits) = (0u32, 0u32);
+    for c in s.bytes().filter(|c| !c.is_ascii_whitespace()) {
+        if c == b'=' {
+            break;
+        }
+        let v = B64.iter().position(|b| *b == c)? as u32;
+        acc = (acc << 6) | v;
+        bits += 6;
+        if bits >= 8 {
+            bits -= 8;
+            out.push((acc >> bits) as u8);
+            acc &= (1 << bits) - 1;
+        }
+    }
+    Some(out)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn base64_round_trips() {
+        for n in 0..10 {
+            let v: Vec<u8> = (0..n).map(|i| (i * 37 + 11) as u8).collect();
+            assert_eq!(base64_decode(&base64_encode(&v)).unwrap(), v);
+        }
+        assert_eq!(base64_encode(b"Man"), "TWFu");
+        assert_eq!(base64_encode(b"Ma"), "TWE=");
+        assert!(base64_decode("TW!u").is_none());
+    }
+
+    #[test]
+    fn logits_round_trip_quantized() {
+        let side = 16;
+        let l: Vec<f32> = (0..side * side).map(|i| (i as f32 - 128.0) / 4.0).collect();
+        let m = SegMask::from_logits(side, &l);
+        let back = m.logits().unwrap();
+        for (a, b) in l.iter().zip(&back) {
+            assert!((a.clamp(-127.0 / SCALE, 127.0 / SCALE) - b).abs() <= 0.5 / SCALE + 1e-6);
+        }
+    }
+
+    #[test]
+    fn a_hostile_document_keeps_at_most_max_detail_patches() {
+        let patch = serde_json::to_value(SegMask::from_logits(4, &[1.0; 16])).unwrap();
+        let shape = serde_json::json!({"kind": "object", "hint": [{"x": 0.5, "y": 0.5}], "detail": vec![patch; 10_000]});
+        let s: crate::MaskShape = serde_json::from_value(shape).unwrap();
+        let crate::MaskShape::Object { detail, .. } = s else { panic!("an Object") };
+        assert_eq!(detail.len(), MAX_DETAIL);
+        // and a whole develop document with them still loads
+        let mut d = crate::DevelopSettings::default();
+        d.masks.push(crate::Mask {
+            id: 1,
+            components: vec![crate::MaskComponent {
+                name: None,
+                op: crate::MaskOp::Add,
+                invert: false,
+                shape: crate::MaskShape::Prompt { text: "x".into(), seg: None, detail: vec![SegMask::from_logits(4, &[1.0; 16]); 50], edge: 0.0 },
+            }],
+            ..Default::default()
+        });
+        let back: crate::DevelopSettings = serde_json::from_str(&serde_json::to_string(&d).unwrap()).unwrap();
+        let crate::MaskShape::Prompt { detail, .. } = &back.masks[0].components[0].shape else { panic!("a Prompt") };
+        assert_eq!(detail.len(), MAX_DETAIL);
+    }
+
+    #[test]
+    fn damaged_data_is_none() {
+        let mut m = SegMask::from_logits(8, &[1.0; 64]);
+        m.side = 9;
+        assert!(m.logits().is_none(), "size mismatch");
+        m.side = 100_000;
+        assert!(m.logits().is_none(), "absurd size");
+        assert!(SegMask { side: 8, data: "not base64 !".into(), rect: None }.logits().is_none());
+        assert!(SegMask { rect: Some([0.5, 0.0, 0.2, 1.0]), ..SegMask::from_logits(2, &[0.0; 4]) }.bounds().is_none());
+    }
+}

crates/develop/src/settings.rs

@@ -772,8 +772,33 @@ pub enum MaskShape {
     Subject,
     Sky,
     Background,
+    /// One object picked by clicks (SAM 3 point prompts): `hint` holds the clicks that include,
+    /// `exclude` the ones that exclude; `seg` the segmentation computed from them.
     Object {
         hint: Vec<Point>,
+        #[serde(default, skip_serializing_if = "Vec::is_empty")]
+        exclude: Vec<Point>,
+        #[serde(default, skip_serializing_if = "Option::is_none")]
+        seg: Option<crate::SegMask>,
+        /// Zoomed-in passes over parts of the image (higher resolution than `seg`), used
+        /// inside their rectangles.
+        #[serde(default, skip_serializing_if = "Vec::is_empty", deserialize_with = "crate::segmask::de_detail")]
+        detail: Vec<crate::SegMask>,
+        /// Edge −100..100: below 0 harder (a steeper transition), above 0 softer (feathered).
+        #[serde(default, skip_serializing_if = "is_zero")]
+        edge: f64,
+    },
+    /// Everything a description names ("sky", "the red car": SAM 3 concept prompts); `seg` is
+    /// the segmentation computed for it.
+    Prompt {
+        text: String,
+        #[serde(default, skip_serializing_if = "Option::is_none")]
+        seg: Option<crate::SegMask>,
+        #[serde(default, skip_serializing_if = "Vec::is_empty", deserialize_with = "crate::segmask::de_detail")]
+        detail: Vec<crate::SegMask>,
+        /// Edge −100..100, as for `Object`.
+        #[serde(default, skip_serializing_if = "is_zero")]
+        edge: f64,
     },
     People {
         person: u32,

crates/engine/Cargo.toml

@@ -30,6 +30,11 @@ serde_json = { workspace = true }
 thiserror = { workspace = true }
 log = { workspace = true }
 ab_glyph = { workspace = true }
+lightcraft-segment = { workspace = true, optional = true }
+
+[features]
+# AI masks with SAM 3 (Object / Describe). Off for the web and CLI builds.
+sam = ["dep:lightcraft-segment"]
 
 [dev-dependencies]
 libc = { workspace = true }

crates/engine/build.rs

@@ -0,0 +1,59 @@
+//! Optional build input: with `CRAFT_FONTS_DIR=<storytold/craft-fonts checkout>`, embed every font
+//! in its `fonts/manifest.txt` as `CRAFT_FONTS` (see src/fonts.rs). Unset, `CRAFT_FONTS` is empty.
+//! Recipe from craft-fonts' docs/integration.md; craft-fonts is never a Cargo dependency, and this
+//! script only reads a local directory (no network).
+//!
+//! wasm32 (the web build) embeds only the UI font, BIZ UDPGothic Regular (~4.5 MB), to keep the
+//! `.wasm` within the web size budget (Cloudflare serves at most 25 MiB per file); the export
+//! watermark falls back to it there. Native builds embed every font.
+use std::fmt::Write as _;
+use std::path::PathBuf;
+
+fn main() {
+    println!("cargo::rerun-if-changed=build.rs");
+    println!("cargo::rerun-if-env-changed=CRAFT_FONTS_DIR");
+    println!("cargo::rerun-if-env-changed=CRAFT_FONTS_REQUIRED");
+    let mut src = String::from("pub static CRAFT_FONTS: &[CraftFont] = &[\n");
+    if let Some(dir) = std::env::var_os("CRAFT_FONTS_DIR").map(PathBuf::from) {
+        match craft_fonts(&dir) {
+            Ok(entries) => src.push_str(&entries),
+            Err(e) if std::env::var_os("CRAFT_FONTS_REQUIRED").is_some() => {
+                println!("cargo::error=CRAFT_FONTS_DIR={}: {e}", dir.display());
+            }
+            Err(e) => println!("cargo::warning=building without craft-fonts: CRAFT_FONTS_DIR={}: {e}", dir.display()),
+        }
+    }
+    src.push_str("];\n");
+    let out = PathBuf::from(std::env::var_os("OUT_DIR").unwrap_or_default()).join("craft_fonts.rs");
+    if let Err(e) = std::fs::write(&out, src) {
+        println!("cargo::error=writing {}: {e}", out.display());
+    }
+}
+
+/// One `CraftFont { .. }` initialiser per manifest line.
+fn craft_fonts(dir: &std::path::Path) -> Result<String, String> {
+    let manifest = dir.join("fonts/manifest.txt");
+    println!("cargo::rerun-if-changed={}", manifest.display());
+    let text = std::fs::read_to_string(&manifest).map_err(|e| format!("{}: {e}", manifest.display()))?;
+    let wasm = std::env::var("CARGO_CFG_TARGET_ARCH").is_ok_and(|a| a == "wasm32");
+    let mut out = String::new();
+    for line in text.lines().map(str::trim).filter(|l| !l.is_empty() && !l.starts_with('#')) {
+        let f: Vec<&str> = line.split(" | ").map(str::trim).collect();
+        let [family, style, file, scripts, ..] = f.as_slice() else {
+            return Err(format!("malformed manifest line: {line}"));
+        };
+        if wasm && (*family, *style) != ("BIZ UDPGothic", "Regular") {
+            continue;
+        }
+        let path = dir.join(file).canonicalize().map_err(|e| format!("{file}: {e}"))?;
+        println!("cargo::rerun-if-changed={}", path.display());
+        let scripts: Vec<String> = scripts.split(',').map(|s| format!("{:?}", s.trim())).collect();
+        let _ = writeln!(
+            out,
+            "    CraftFont {{ family: {family:?}, style: {style:?}, scripts: &[{}], bytes: include_bytes!({:?}) }},",
+            scripts.join(", "),
+            path.display().to_string(),
+        );
+    }
+    Ok(out)
+}

crates/engine/src/availability.rs

@@ -0,0 +1,215 @@
+//! Is a file there? — answered without blocking the caller.
+//!
+//! On a sleeping NAS, a dropped share or a USB drive spinning up, one `stat` can take as long as
+//! the OS or SMB timeout. The UI asks about files every frame (grid cells, the Info panel, the
+//! Missing Photos view), so in the app the answers come from a cache that a worker thread fills
+//! ([`Availability::run_in_background`]): an unknown file is reported as `None` ("assume it is
+//! there"; the render worker finds out if it isn't), known answers are rechecked after
+//! [`RECHECK`]. Everywhere else (CLI, MCP, tests) the default is synchronous: every question is a
+//! fresh check, as before.
+
+use std::collections::{HashMap, HashSet, VecDeque};
+use std::sync::{Arc, Mutex, MutexGuard, PoisonError};
+use std::time::Duration;
+
+/// Checks whether a path exists (injectable: tests use a slow one).
+pub type ExistsProbe = Arc<dyn Fn(&str) -> bool + Send + Sync>;
+/// Called (from the worker) when an answer changed, e.g. to repaint the UI.
+pub type Waker = Arc<dyn Fn() + Send + Sync>;
+
+/// How long a cached answer is used before it is checked again (it is still returned meanwhile).
+pub const RECHECK: Duration = Duration::from_secs(15);
+
+fn fs_exists(path: &str) -> bool {
+    // the browser build has no file system: its originals are always "there"
+    cfg!(target_arch = "wasm32") || std::path::Path::new(path).exists()
+}
+
+#[derive(Default)]
+struct State {
+    /// path → (exists, when checked)
+    known: HashMap<String, (bool, std::time::Instant)>,
+    queue: VecDeque<String>,
+    queued: HashSet<String>,
+    worker: bool,
+    /// Bumped whenever an answer changes (callers recompute what depends on it).
+    generation: u64,
+}
+
+fn lock(m: &Mutex<State>) -> MutexGuard<'_, State> {
+    m.lock().unwrap_or_else(PoisonError::into_inner)
+}
+
+/// File availability, synchronous or cached + background-checked. Cloning shares the cache.
+#[derive(Clone)]
+pub struct Availability {
+    probe: ExistsProbe,
+    background: Option<Waker>,
+    state: Arc<Mutex<State>>,
+}
+
+impl Default for Availability {
+    fn default() -> Self {
+        Self { probe: Arc::new(fs_exists), background: None, state: Arc::default() }
+    }
+}
+
+impl std::fmt::Debug for Availability {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.debug_struct("Availability").field("background", &self.background.is_some()).finish()
+    }
+}
+
+impl Availability {
+    /// Replace the existence check (tests: a slow or counting probe). Forgets cached answers.
+    pub fn set_probe(&mut self, probe: ExistsProbe) {
+        self.probe = probe;
+        let mut st = lock(&self.state);
+        st.known.clear();
+        st.generation += 1;
+    }
+
+    /// Answer from the cache and check on a worker thread from now on; `wake` runs when an
+    /// answer changed. No effect in the browser build (no threads, no file system).
+    pub fn run_in_background(&mut self, wake: Waker) {
+        if cfg!(target_arch = "wasm32") {
+            return;
+        }
+        self.background = Some(wake);
+    }
+
+    /// The existence check itself (blocking: for worker threads, e.g. the Rename preview's).
+    pub fn probe(&self) -> ExistsProbe {
+        self.probe.clone()
+    }
+
+    pub fn is_background(&self) -> bool {
+        self.background.is_some()
+    }
+
+    /// Does `path` exist? Synchronous mode: checked now. Background mode: the cached answer
+    /// (`None` while unknown); unknown or stale answers are queued for the worker.
+    pub fn exists(&self, path: &str) -> Option<bool> {
+        let Some(wake) = &self.background else {
+            return Some((self.probe)(path));
+        };
+        let mut st = lock(&self.state);
+        let now = std::time::Instant::now();
+        let cached = st.known.get(path).copied();
+        if cached.is_none_or(|(_, at)| now.saturating_duration_since(at) >= RECHECK) && !st.queued.contains(path) {
+            st.queued.insert(path.to_string());
+            st.queue.push_back(path.to_string());
+            if !st.worker {
+                st.worker = true;
+                drop(st);
+                self.spawn_worker(wake.clone());
+                return cached.map(|c| c.0);
+            }
+        }
+        cached.map(|c| c.0)
+    }
+
+    /// Known to be missing (unknown counts as present).
+    pub fn is_offline(&self, path: &str) -> bool {
+        self.exists(path) == Some(false)
+    }
+
+    /// Changes whenever a cached answer changes.
+    pub fn generation(&self) -> u64 {
+        lock(&self.state).generation
+    }
+
+    /// Paths waiting for the worker.
+    pub fn pending(&self) -> usize {
+        lock(&self.state).queue.len()
+    }
+
+    fn spawn_worker(&self, wake: Waker) {
+        let (state, probe) = (self.state.clone(), self.probe.clone());
+        let started = std::thread::Builder::new().name("lc-availability".into()).spawn(move || {
+            loop {
+                let path = {
+                    let mut st = lock(&state);
+                    let Some(p) = st.queue.pop_front() else {
+                        st.worker = false;
+                        return;
+                    };
+                    p
+                };
+                let ok = probe(&path);
+                let changed = {
+                    let mut st = lock(&state);
+                    st.queued.remove(&path);
+                    let prev = st.known.insert(path, (ok, std::time::Instant::now()));
+                    let changed = prev.map(|p| p.0) != Some(ok);
+                    if changed {
+                        st.generation += 1;
+                    }
+                    changed
+                };
+                if changed {
+                    wake();
+                }
+            }
+        });
+        if started.is_err() {
+            // try again on the next question
+            lock(&self.state).worker = false;
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use std::sync::atomic::{AtomicUsize, Ordering};
+
+    #[test]
+    fn synchronous_by_default() {
+        let mut a = Availability::default();
+        let n = Arc::new(AtomicUsize::new(0));
+        let c = n.clone();
+        a.set_probe(Arc::new(move |p| {
+            c.fetch_add(1, Ordering::SeqCst);
+            p == "here"
+        }));
+        assert_eq!(a.exists("here"), Some(true));
+        assert_eq!(a.exists("gone"), Some(false));
+        assert_eq!(a.exists("gone"), Some(false));
+        assert_eq!(n.load(Ordering::SeqCst), 3, "every question is a fresh check");
+    }
+
+    #[test]
+    fn background_answers_from_the_cache_without_blocking() {
+        let mut a = Availability::default();
+        let caller = std::thread::current().id();
+        let on_caller = Arc::new(AtomicUsize::new(0));
+        let c = on_caller.clone();
+        a.set_probe(Arc::new(move |p| {
+            if std::thread::current().id() == caller {
+                c.fetch_add(1, Ordering::SeqCst);
+            }
+            std::thread::sleep(Duration::from_millis(200)); // a sleeping NAS
+            p == "here"
+        }));
+        let woke = Arc::new(AtomicUsize::new(0));
+        let w = woke.clone();
+        a.run_in_background(Arc::new(move || {
+            w.fetch_add(1, Ordering::SeqCst);
+        }));
+        let t0 = std::time::Instant::now();
+        assert_eq!(a.exists("here"), None, "unknown at first");
+        assert_eq!(a.exists("gone"), None);
+        assert!(t0.elapsed() < Duration::from_millis(150), "the caller never waits for the probe");
+        let deadline = std::time::Instant::now() + Duration::from_secs(20);
+        while (a.exists("here").is_none() || a.exists("gone").is_none()) && std::time::Instant::now() < deadline {
+            std::thread::sleep(Duration::from_millis(10));
+        }
+        assert_eq!(a.exists("here"), Some(true));
+        assert_eq!(a.exists("gone"), Some(false));
+        assert!(a.is_offline("gone") && !a.is_offline("here") && !a.is_offline("unknown"));
+        assert_eq!(on_caller.load(Ordering::SeqCst), 0, "never probed on the calling thread");
+        assert!(woke.load(Ordering::SeqCst) >= 2);
+        assert!(a.generation() >= 2);
+    }
+}

crates/engine/src/camera_preview.rs

@@ -0,0 +1,777 @@
+//! Estimate the starting look of a raw without a camera colour matrix (Sony ARW, Nikon NEF) from its
+//! own JPEG. Colour and luminance are fitted separately; the JPEG supplies correspondences only,
+//! never output pixels or a replacement for RAW editing.
+//! A global matrix can't follow the camera's hue-dependent rendering (the best matrix rendered a
+//! lime shirt olive that the camera kept lime): a hue/saturation table fitted to the residuals
+//! (applied like a DNG `ProfileHueSatMap`) corrects that when it also improves the held-out pixels.
+use lightcraft_color::{D50, D65, Mat3, PROPHOTO, REC2020, bradford, luminance_2020};
+use lightcraft_pipeline::tone::{CameraTone, ToneMap};
+use lightcraft_raster::{
+    Rgb32f,
+    resample::{Filter, fit},
+};
+use lightcraft_raw::{RawFormat, RawImage, color::CameraTransform, profile::HsvTable};
+
+#[derive(Clone, Debug)]
+pub(crate) struct CameraLook {
+    pub matrix: Mat3,
+    pub tone: CameraTone,
+    /// Hue/saturation correction after `matrix`, in linear ProPhoto RGB (DNG `ProfileHueSatMap`).
+    pub hue_sat: Option<HsvTable>,
+}
+
+/// Long edge of the sensor/JPEG proxy a single photo's look is fitted on (the acceptance gates
+/// below were set at this size).
+const PROXY: usize = 96;
+/// Long edge of the proxies pooled for a camera profile: small objects (a shirt) get 4× the samples.
+pub(crate) const PROFILE_PROXY: usize = 192;
+
+/// Raw formats whose decoder supplies vendor white-balance multipliers but no camera colour matrix:
+/// their starting look is fitted to the file's own JPEG, and white balance is relative to the
+/// as-shot look (`docs/camera-preview-colour.md`). The catalog's `Photo::relative_wb` matches the
+/// same formats by file extension.
+pub(crate) fn file_local_look(format: RawFormat) -> bool {
+    matches!(format, RawFormat::Arw | RawFormat::Nef | RawFormat::Nrw)
+}
+
+pub(crate) fn fit_preview(raw: &RawImage, bytes: &[u8], transform: &CameraTransform) -> Option<CameraLook> {
+    if !transform.matrix_is_fallback || !file_local_look(raw.format) {
+        return None;
+    }
+    let (sensor, reference) = proxies(raw, bytes, transform, PROXY)?;
+    // A camera profile pooled from many photos knows colours this photo shows too little of;
+    // only the tone and chroma curves are fitted per photo (DRO and picture styles vary).
+    let profile = raw.metadata.model.as_deref().and_then(crate::camera_profiles::get);
+    let colour = profile.as_ref().and_then(|p| Some((p.matrix().mul(&transform.matrix.inverse()?), p.hue_sat.clone())));
+    let look = fit_pairs_with(&sensor, &reference, colour)?;
+    if lightcraft_pipeline::profiling() {
+        eprintln!(
+            "[profile] {:?} camera look: {:?}, {:?}, hue/sat table {}, camera profile {}",
+            raw.format,
+            look.matrix.0,
+            look.tone,
+            look.hue_sat.is_some(),
+            profile.is_some()
+        );
+    }
+    Some(look)
+}
+
+/// Same-size proxies of the sensor (white-balanced, baseline exposure, through `transform`'s
+/// matrix: the generic camera ≈ sRGB model) and of the file's embedded camera JPEG (linear Rec.2020).
+fn proxies(raw: &RawImage, bytes: &[u8], transform: &CameraTransform, size: usize) -> Option<(Rgb32f, Rgb32f)> {
+    let jpeg = lightcraft_raw::embedded_preview(bytes)?;
+    let edge = (2 * size).max(384) as u32;
+    let decoded = lightcraft_codecs::decode(&jpeg, lightcraft_codecs::DecodeOptions { max_size: Some((edge, edge)), max_pixels: 64_000_000 }).ok()?;
+    let reference = decoded.to_working();
+    let crop = raw.crop.clipped(raw.active_area.width, raw.active_area.height);
+    if crop.width == 0 || crop.height == 0 || reference.width == 0 || reference.height == 0 {
+        return None;
+    }
+    let aspect = crop.width as f64 / crop.height as f64;
+    if (reference.width as f64 / reference.height as f64 / aspect - 1.0).abs() > 0.02 {
+        return None;
+    }
+    // Fixed, bounded proxy: the selected look cannot depend on thumbnail/export resolution.
+    let k = (crop.width.max(crop.height).div_ceil(edge as usize).max(2)).div_ceil(2) * 2;
+    let sensor = raw.develop_binned(k, 0.99).ok()??;
+    let mut sensor = fit(&sensor, size, size, Filter::Box);
+    let reference = fit(&reference, sensor.width, sensor.height, Filter::Box);
+    let gain = 2f32.powf(transform.baseline_exposure as f32);
+    sensor.map_in_place(|p| transform.matrix.apply_f32(std::array::from_fn(|i| p[i] * transform.wb[i] * gain)));
+    Some((sensor, reference))
+}
+
+/// Colour training pairs of one raw for a camera profile: white-balanced camera RGB (with the
+/// baseline exposure) → its camera JPEG (linear Rec.2020). `None` for formats with their own
+/// colour matrices, other files or unusable previews.
+pub(crate) fn profile_pairs(raw: &RawImage, bytes: &[u8]) -> Option<Vec<([f64; 3], [f64; 3])>> {
+    if !file_local_look(raw.format) || lightcraft_raw::color::has_matrix(&raw.color) {
+        return None;
+    }
+    let transform = lightcraft_raw::color::camera_transform(raw, lightcraft_raw::color::as_shot_white_xy(raw));
+    let (sensor, reference) = proxies(raw, bytes, &transform, PROFILE_PROXY)?;
+    let to_camera = transform.matrix.inverse()?;
+    let (pairs, _) = collect_pairs(&sensor, &reference)?;
+    Some(pairs.into_iter().map(|(x, y)| (to_camera.apply(x), y)).collect())
+}
+
+/// A camera profile's colour model (matrix from white-balanced camera RGB, hue/saturation table)
+/// fitted to pairs pooled from many photos.
+pub(crate) fn fit_profile(pairs: &[([f64; 3], [f64; 3])]) -> Option<(Mat3, Option<HsvTable>)> {
+    let matrix = fit_matrix(pairs)?;
+    Some((matrix, fit_hue_sat(pairs, &matrix)))
+}
+
+/// A fit must cut the held-out squared error to below this share of the fallback's.
+const MIN_IMPROVEMENT: f64 = 0.7;
+/// ...and stay within this per-channel RMS of the camera JPEG (linear display values). On public
+/// raw.pixls.us samples (eight Sony bodies) good fits that still beat the fallback 1.5–3× landed
+/// at 0.065–0.093 (camera local tone, vignetting and lens processing that a global matrix + curve
+/// cannot follow): visibly better renders that 0.055 rejected.
+const MAX_HOLDOUT_RMS: f64 = 0.10;
+
+fn luma(p: [f64; 3]) -> f64 {
+    p[0] * 0.2627 + p[1] * 0.6780 + p[2] * 0.0593
+}
+
+/// The finish stage's tone map and chroma curve (`lightcraft_pipeline::finish`).
+fn displayed(scene: [f64; 3], tone: &ToneMap) -> [f64; 3] {
+    let scene = scene.map(|v| v.max(0.0));
+    let y = luma(scene);
+    if y <= 0.0 {
+        return [0.0; 3];
+    }
+    let o = f64::from(tone.apply(y as f32));
+    let k = f64::from(tone.chroma_scale(o as f32));
+    scene.map(|v| o + (v * o / y - o) * k)
+}
+
+#[cfg(test)]
+fn fit_pairs(sensor: &Rgb32f, reference: &Rgb32f) -> Option<CameraLook> {
+    fit_pairs_with(sensor, reference, None)
+}
+
+/// Training pairs (sensor → JPEG, unclipped midtones) and the wider set including highlights
+/// (for the chroma curve); `None` when too few, or the photo has too little colour.
+type Pairs = Vec<([f64; 3], [f64; 3])>;
+fn collect_pairs(sensor: &Rgb32f, reference: &Rgb32f) -> Option<(Pairs, Pairs)> {
+    if (sensor.width, sensor.height) != (reference.width, reference.height) || sensor.data.len() != reference.data.len() {
+        return None;
+    }
+    let mut pairs = Vec::new();
+    // Highlights too (camera JPEGs bleach colours toward white there), for the chroma curve only.
+    let mut bright = Vec::new();
+    let mut colour = 0;
+    for (input, output) in sensor.data.iter().zip(&reference.data) {
+        let y = luminance_2020(*output);
+        if !input.iter().all(|v| v.is_finite() && *v > 0.001 && *v < 1.5) || !output.iter().all(|v| v.is_finite() && *v >= 0.0) {
+            continue;
+        }
+        if (0.015..=1.0).contains(&y) {
+            bright.push((input.map(f64::from), output.map(f64::from)));
+        }
+        if !output.iter().all(|v| *v > 0.004 && *v < 0.98) || !(0.015..0.85).contains(&y) {
+            continue;
+        }
+        let min = output.iter().copied().fold(f32::INFINITY, f32::min);
+        let max = output.iter().copied().fold(0.0, f32::max);
+        colour += usize::from(max - min > 0.05);
+        pairs.push((input.map(f64::from), output.map(f64::from)));
+    }
+    (pairs.len() >= 256 && colour >= pairs.len() / 20).then_some((pairs, bright))
+}
+
+/// Ridge-regularised 3×3 chromaticity matrix (luminance-normalised RGB) on the training pairs.
+fn fit_matrix(pairs: &[([f64; 3], [f64; 3])]) -> Option<Mat3> {
+    let mut gram = [[0.0; 3]; 3];
+    let mut cross = [[0.0; 3]; 3];
+    for (i, (x, y)) in pairs.iter().enumerate() {
+        if i % 3 == 0 {
+            continue;
+        }
+        let (lx, ly) = (luma(*x), luma(*y));
+        if lx <= 0.0 || ly <= 0.0 {
+            continue;
+        }
+        for row in 0..3 {
+            for col in 0..3 {
+                // Normalising by luminance prevents a camera S-curve from corrupting colour.
+                gram[row][col] += x[row] * x[col] / (lx * lx);
+                cross[row][col] += y[row] * x[col] / (ly * lx);
+            }
+        }
+    }
+    let trace: f64 = (0..3).map(|i| gram[i][i]).sum();
+    let inverse = Mat3(gram).inverse()?;
+    let condition = trace * (0..3).map(|i| inverse.0[i][i].abs()).sum::<f64>();
+    if trace <= 0.0 || !condition.is_finite() || condition > 1e6 {
+        return None;
+    }
+    let regularization = trace * 1e-4;
+    for i in 0..3 {
+        gram[i][i] += regularization;
+        cross[i][i] += regularization;
+    }
+    let matrix = Mat3(cross).mul(&Mat3(gram).inverse()?);
+    matrix.0.iter().flatten().all(|v| v.is_finite() && v.abs() < 8.0).then_some(matrix)
+}
+
+/// The photo's look: its own matrix (with and without a hue/saturation table), or the given
+/// colour model (a camera profile's, in the sensor proxy's space), each completed with a tone
+/// and chroma curve fitted to this photo.
+fn fit_pairs_with(sensor: &Rgb32f, reference: &Rgb32f, colour: Option<(Mat3, Option<HsvTable>)>) -> Option<CameraLook> {
+    let (pairs, bright) = collect_pairs(sensor, reference)?;
+    let candidates = match colour {
+        Some(given) => vec![given],
+        None => {
+            let matrix = fit_matrix(&pairs)?;
+            vec![(matrix, fit_hue_sat(&pairs, &matrix)), (matrix, None)]
+        }
+    };
+    // Matrix + table when the table helps the held-out pixels, else the matrix alone. Chosen by
+    // error in gamma-encoded display values (closer to what is seen: in linear values a slightly
+    // missed bright rock outweighs a clearly wrong dark shirt); the acceptance gates below stay linear.
+    let mut best: Option<(f64, f64, usize, CameraLook)> = None;
+    for (matrix, hue_sat) in candidates {
+        let correction = hue_sat.as_ref().and_then(HueSat::new);
+        let colour = |x: [f64; 3]| {
+            let p = matrix.apply(x);
+            correction.as_ref().map_or(p, |c| c.apply(p.map(|v| v as f32)).map(f64::from))
+        };
+        let tone_pairs: Vec<_> =
+            pairs.iter().enumerate().filter(|(i, _)| i % 3 != 0).map(|(_, (x, y))| (luma(colour(*x).map(|v| v.max(0.0))), luma(*y))).collect();
+        let Some(curve) = fit_tone(tone_pairs) else { continue };
+        let mut look = CameraLook { matrix, tone: curve, hue_sat: hue_sat.clone() };
+        if let Some(tone) = fit_chroma(&bright, &look) {
+            look.tone = tone;
+        }
+        let tone = ToneMap::camera(&look.tone, 0.0, 0.0, 0.0);
+        let (mut linear, mut perceptual, mut samples) = (0.0, 0.0, 0);
+        for (x, target) in pairs.iter().step_by(3) {
+            let corrected = displayed(colour(*x), &tone);
+            for c in 0..3 {
+                linear += (corrected[c] - target[c]).powi(2);
+                perceptual += (corrected[c].max(0.0).powf(1.0 / 2.2) - target[c].max(0.0).powf(1.0 / 2.2)).powi(2);
+                samples += 1;
+            }
+        }
+        if linear.is_finite() && perceptual.is_finite() && best.as_ref().is_none_or(|b| perceptual < b.0) {
+            best = Some((perceptual, linear, samples, look));
+        }
+    }
+    let (_, after, samples, look) = best?;
+    let original_tone = ToneMap::new(0.0, 0.0, 0.0);
+    let before: f64 = pairs
+        .iter()
+        .step_by(3)
+        .map(|(x, target)| {
+            let original = displayed(*x, &original_tone);
+            (0..3).map(|c| (original[c] - target[c]).powi(2)).sum::<f64>()
+        })
+        .sum();
+    if lightcraft_pipeline::profiling() {
+        eprintln!(
+            "[profile] camera look holdout RMS {:.5} -> {:.5} ({samples} channels)",
+            (before / samples as f64).sqrt(),
+            (after / samples as f64).sqrt()
+        );
+    }
+    if samples == 0 || after >= before * MIN_IMPROVEMENT || after / samples as f64 > MAX_HOLDOUT_RMS.powi(2) {
+        return None;
+    }
+    Some(look)
+}
+
+/// Linear Rec.2020 D65 → linear ProPhoto RGB D50, the space DNG hue/saturation tables work in.
+fn to_prophoto() -> Mat3 {
+    PROPHOTO.from_xyz().mul(&bradford(D65, D50)).mul(&REC2020.to_xyz())
+}
+
+/// A fitted [`CameraLook::hue_sat`] table, ready to apply to linear Rec.2020 pixels. It changes
+/// hue and saturation only: luminance is restored, the camera tone curve owns it.
+pub(crate) struct HueSat<'a> {
+    table: &'a HsvTable,
+    to: [[f32; 3]; 3],
+    from: [[f32; 3]; 3],
+}
+
+impl<'a> HueSat<'a> {
+    pub fn new(table: &'a HsvTable) -> Option<HueSat<'a>> {
+        let to = to_prophoto();
+        Some(HueSat { table, to: to.to_f32(), from: to.inverse()?.to_f32() })
+    }
+
+    #[inline]
+    pub fn apply(&self, rgb: [f32; 3]) -> [f32; 3] {
+        let mul = |m: &[[f32; 3]; 3], v: [f32; 3]| -> [f32; 3] { std::array::from_fn(|i| m[i][0] * v[0] + m[i][1] * v[1] + m[i][2] * v[2]) };
+        let out = mul(&self.from, self.table.apply(mul(&self.to, rgb)));
+        let (before, after) = (luminance_2020(rgb), luminance_2020(out));
+        if before > 0.0 && after > 0.0 && out.iter().all(|v| v.is_finite()) { out.map(|v| v * before / after) } else { rgb }
+    }
+}
+
+/// HSV hue (degrees) and saturation; `None` for black or non-finite colours.
+fn hue_saturation(p: [f64; 3]) -> Option<(f64, f64)> {
+    let max = p[0].max(p[1]).max(p[2]);
+    let min = p[0].min(p[1]).min(p[2]);
+    if !(max.is_finite() && min.is_finite()) || max <= 0.0 {
+        return None;
+    }
+    let d = max - min;
+    if d <= 0.0 {
+        return Some((0.0, 0.0));
+    }
+    let h = if max == p[0] {
+        ((p[1] - p[2]) / d).rem_euclid(6.0)
+    } else if max == p[1] {
+        (p[2] - p[0]) / d + 2.0
+    } else {
+        (p[0] - p[1]) / d + 4.0
+    };
+    Some((h * 60.0, d / max))
+}
+
+/// Table resolution: 5° hue steps (a coarser grid blurred the lime shirt into neighbouring browns
+/// that want the opposite shift), saturation 0, 0.25 … 1. Value is not an axis: tone is fitted separately.
+const TABLE_HUES: usize = 72;
+const TABLE_SATS: usize = 5;
+/// Value levels (sRGB-encoded, as DNG tables with encoding 1): cameras turn dark yellows toward
+/// orange but bright yellow-greens toward green, which one shift per hue averages away.
+const TABLE_VALS: usize = 5;
+/// Kernel widths around each table node (hue in degrees, saturation, encoded value).
+const KERNEL_HUE: f64 = 2.5;
+const KERNEL_SAT: f64 = 0.15;
+const KERNEL_VAL: f64 = 0.12;
+/// Kernel weight at which a node keeps half of its estimate; sparse nodes shrink to identity.
+const SHRINK_WEIGHT: f64 = 5.0;
+
+/// Fit hue shifts and saturation scales of the training pairs left after `matrix`, per (hue,
+/// saturation) node, kernel-weighted and shrunk toward identity where the photo has few samples.
+/// Saturation 0 stays identity, so neutrals are never tinted.
+fn fit_hue_sat(pairs: &[([f64; 3], [f64; 3])], matrix: &Mat3) -> Option<HsvTable> {
+    let to = to_prophoto();
+    let samples: Vec<(f64, f64, f64, f64, f64)> = pairs
+        .iter()
+        .enumerate()
+        .filter(|(i, _)| i % 3 != 0)
+        .filter_map(|(_, (x, y))| {
+            let p = to.apply(matrix.apply(*x));
+            let (hp, sp) = hue_saturation(p)?;
+            let value = f64::from(lightcraft_color::transfer::linear_to_srgb(p[0].max(p[1]).max(p[2]).min(1.0) as f32));
+            let (ht, st) = hue_saturation(to.apply(*y))?;
+            // hue is meaningless near neutral
+            if sp < 0.08 || st < 0.02 {
+                return None;
+            }
+            let shift = ((ht - hp + 180.0).rem_euclid(360.0) - 180.0).clamp(-30.0, 30.0);
+            let log_scale = (st / sp).ln().clamp(-0.7, 0.7);
+            Some((hp, sp.min(1.0), value, shift, log_scale))
+        })
+        .collect();
+    if samples.len() < 64 {
+        return None;
+    }
+    // Samples by table hue step: a node only looks at hues within its kernel's reach.
+    let step = 360.0 / TABLE_HUES as f64;
+    let mut by_hue: Vec<Vec<(f64, f64, f64, f64, f64)>> = vec![Vec::new(); TABLE_HUES];
+    for sample in samples {
+        if let Some(bin) = by_hue.get_mut(((sample.0.rem_euclid(360.0) / step) as usize).min(TABLE_HUES - 1)) {
+            bin.push(sample);
+        }
+    }
+    let reach = (4.0 * KERNEL_HUE / step).ceil() as usize + 1;
+    use rayon::prelude::*;
+    let data: Vec<[f32; 3]> = (0..TABLE_VALS * TABLE_HUES * TABLE_SATS)
+        .into_par_iter()
+        .map(|index| {
+            let (v, h, s) = (index / (TABLE_HUES * TABLE_SATS), index / TABLE_SATS % TABLE_HUES, index % TABLE_SATS);
+            if s == 0 {
+                return [0.0, 1.0, 1.0];
+            }
+            let (val, hue, sat) = (v as f64 / (TABLE_VALS - 1) as f64, h as f64 * step, s as f64 / (TABLE_SATS - 1) as f64);
+            let (mut weight, mut shift, mut log_scale) = (0.0, 0.0, 0.0);
+            for offset in 0..=2 * reach {
+                let Some(bin) = by_hue.get((h + TABLE_HUES * 2 + offset - reach) % TABLE_HUES) else { continue };
+                for &(hp, sp, vp, dh, ls) in bin {
+                    let dhue = (hp - hue + 180.0).rem_euclid(360.0) - 180.0;
+                    if dhue.abs() > 4.0 * KERNEL_HUE {
+                        continue;
+                    }
+                    let d2 = (dhue / KERNEL_HUE).powi(2) + ((sp - sat) / KERNEL_SAT).powi(2) + ((vp - val) / KERNEL_VAL).powi(2);
+                    let k = (-0.5 * d2).exp() * sp;
+                    weight += k;
+                    shift += k * dh;
+                    log_scale += k * ls;
+                }
+            }
+            if weight <= 0.0 {
+                return [0.0, 1.0, 1.0];
+            }
+            let shrink = 1.0 / (weight + SHRINK_WEIGHT);
+            [(shift * shrink) as f32, (log_scale * shrink).exp() as f32, 1.0]
+        })
+        .collect();
+    data.iter().all(|e| e.iter().all(|v| v.is_finite())).then_some(HsvTable {
+        hue_divisions: TABLE_HUES,
+        sat_divisions: TABLE_SATS,
+        val_divisions: TABLE_VALS,
+        data,
+        srgb_value: true,
+    })
+}
+
+/// Kernel width of the chroma curve's nodes (display luminance) and the weight at which a node
+/// keeps half of its estimate.
+const CHROMA_KERNEL: f64 = 0.08;
+const CHROMA_SHRINK: f64 = 2.0;
+
+/// The look's tone curve with a chroma-by-display-luminance curve fitted to `pairs` (two thirds
+/// train, one third held out), when that lowers the held-out error. Colourfulness is compared as
+/// the distance from neutral of luminance-normalised RGB.
+fn fit_chroma(pairs: &[([f64; 3], [f64; 3])], look: &CameraLook) -> Option<CameraTone> {
+    let correction = look.hue_sat.as_ref().and_then(HueSat::new);
+    let scene = |x: &[f64; 3]| {
+        let p = look.matrix.apply(*x);
+        correction.as_ref().map_or(p, |c| c.apply(p.map(|v| v as f32)).map(f64::from))
+    };
+    let tone = ToneMap::camera(&look.tone, 0.0, 0.0, 0.0);
+    let predict = |x: &[f64; 3]| displayed(scene(x), &tone);
+    let chroma = |p: [f64; 3]| {
+        let y = luma(p);
+        (y > 0.0).then(|| p.iter().map(|v| (v / y - 1.0).powi(2)).sum::<f64>().sqrt())
+    };
+    let samples: Vec<(f64, f64, f64)> = pairs
+        .iter()
+        .enumerate()
+        .filter(|(i, _)| i % 3 != 0)
+        .filter_map(|(_, (x, y))| {
+            let p = predict(x);
+            let (cp, cy) = (chroma(p)?, chroma(*y)?);
+            (cp > 0.05).then(|| (luma(p), cp, (cy.max(1e-3) / cp).ln().clamp(0.05f64.ln(), 2.5f64.ln())))
+        })
+        .collect();
+    if samples.len() < 64 {
+        return None;
+    }
+    let mut curve = [1.0f32; lightcraft_pipeline::tone::CHROMA_N];
+    for (j, node) in curve.iter_mut().enumerate() {
+        let at = j as f64 / (lightcraft_pipeline::tone::CHROMA_N - 1) as f64;
+        let (mut weight, mut sum) = (0.0, 0.0);
+        for &(o, cp, log_ratio) in &samples {
+            let k = (-0.5 * ((o - at) / CHROMA_KERNEL).powi(2)).exp() * cp;
+            weight += k;
+            sum += k * log_ratio;
+        }
+        *node = (sum / (weight + CHROMA_SHRINK)).exp() as f32;
+    }
+    let fitted = look.tone.with_chroma(curve)?;
+    let with = ToneMap::camera(&fitted, 0.0, 0.0, 0.0);
+    let error = |map: &ToneMap| -> f64 {
+        pairs
+            .iter()
+            .step_by(3)
+            .map(|(x, y)| {
+                let p = displayed(scene(x), map);
+                (0..3).map(|c| (p[c] - y[c]).powi(2)).sum::<f64>()
+            })
+            .sum()
+    };
+    let (before, after) = (error(&tone), error(&with));
+    if lightcraft_pipeline::profiling() {
+        eprintln!("[profile] ARW chroma curve {curve:?}: held-out error {before:.4} -> {after:.4}");
+    }
+    (after.is_finite() && after < before).then_some(fitted)
+}
+
+fn median(values: &mut [f64]) -> Option<f64> {
+    values.sort_by(f64::total_cmp);
+    values.get(values.len() / 2).copied()
+}
+
+fn fit_tone(mut pairs: Vec<(f64, f64)>) -> Option<CameraTone> {
+    if pairs.len() < 128 || !pairs.iter().all(|(x, y)| x.is_finite() && *x > 0.0 && y.is_finite()) {
+        return None;
+    }
+    pairs.sort_by(|a, b| a.0.total_cmp(&b.0));
+    let mut knots = [[0.0; 2]; 32];
+    for (i, knot) in knots.iter_mut().enumerate() {
+        let bin = pairs.get(i * pairs.len() / 32..(i + 1) * pairs.len() / 32)?;
+        let mut xs: Vec<_> = bin.iter().map(|p| p.0).collect();
+        let mut ys: Vec<_> = bin.iter().map(|p| p.1).collect();
+        *knot = [median(&mut xs)? as f32, median(&mut ys)? as f32];
+    }
+    if knots[31][0] < knots[0][0] * 1.5 {
+        return None;
+    }
+    // Pool adjacent violating bins (isotonic regression): no reversals or arbitrary polynomial.
+    let mut blocks: Vec<(f32, usize)> = Vec::new();
+    for knot in knots {
+        blocks.push((knot[1], 1));
+        while blocks.len() >= 2 {
+            let (a, an) = *blocks.get(blocks.len() - 2)?;
+            let (b, bn) = *blocks.last()?;
+            if a <= b {
+                break;
+            }
+            blocks.truncate(blocks.len() - 2);
+            blocks.push(((a * an as f32 + b * bn as f32) / (an + bn) as f32, an + bn));
+        }
+    }
+    let mut i = 0;
+    for (y, n) in blocks {
+        for knot in knots.get_mut(i..i + n)? {
+            knot[1] = y;
+        }
+        i += n;
+    }
+    CameraTone::new(knots)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    #[test]
+    fn separates_nonlinear_tone_from_colour_and_keeps_sensor_headroom() {
+        let known = Mat3([[1.8, -0.4, -0.1], [-0.2, 1.5, -0.1], [-0.05, -0.3, 1.7]]);
+        let mut sensor = Rgb32f::new(64, 64);
+        let mut reference = sensor.clone();
+        for (i, (src, dst)) in sensor.data.iter_mut().zip(&mut reference.data).enumerate() {
+            let ev = 0.05 + (i % 31) as f32 * 0.017;
+            *src = [ev * (0.8 + (i % 11) as f32 * 0.025), ev, ev * (0.8 + (i % 17) as f32 * 0.014)];
+            let p = known.apply_f32(*src);
+            let y = luminance_2020(p);
+            *dst = p.map(|v| v * (1.0 - (-2.5 * y).exp()) / y);
+        }
+        let original = sensor.clone();
+        let fit = fit_pairs(&sensor, &reference).unwrap();
+        assert_eq!(sensor.data, original.data);
+        let tone = ToneMap::camera(&fit.tone, 0.0, 0.0, 0.0);
+        let error: f64 = sensor
+            .data
+            .iter()
+            .zip(&reference.data)
+            .map(|(x, y)| {
+                let p = displayed(fit.matrix.apply(x.map(f64::from)), &tone);
+                (0..3).map(|c| (p[c] - f64::from(y[c])).powi(2)).sum::<f64>() / 3.0
+            })
+            .sum::<f64>()
+            / sensor.data.len() as f64;
+        assert!(error.sqrt() < 0.025, "{error}");
+        // The colour transform is homogeneous; tone mapping happens only after exposure.
+        let p = fit.matrix.apply([2.0, 2.0, 2.0]);
+        assert!(luma(p) > 1.0);
+        assert!(tone.apply(0.2) < tone.apply(0.4));
+    }
+    #[test]
+    fn accepts_a_much_better_fit_despite_local_camera_processing() {
+        // The camera JPEG departs from any global matrix + curve (local tone, vignetting): ±0.12
+        // per-pixel deviations, ~0.07 RMS. The fit is still far closer than the fallback.
+        let known = Mat3([[1.8, -0.4, -0.1], [-0.2, 1.5, -0.1], [-0.05, -0.3, 1.7]]);
+        let mut sensor = Rgb32f::new(64, 64);
+        let mut reference = sensor.clone();
+        let mut seed = 0x2545_f491_u32;
+        for (i, (src, dst)) in sensor.data.iter_mut().zip(&mut reference.data).enumerate() {
+            let ev = 0.05 + (i % 31) as f32 * 0.017;
+            *src = [ev * (0.8 + (i % 11) as f32 * 0.025), ev, ev * (0.8 + (i % 17) as f32 * 0.014)];
+            let p = known.apply_f32(*src);
+            let y = luminance_2020(p);
+            *dst = p.map(|v| {
+                seed ^= seed << 13;
+                seed ^= seed >> 17;
+                seed ^= seed << 5;
+                let noise = (seed % 2001) as f32 / 1000.0 - 1.0;
+                (v * (1.0 - (-2.5 * y).exp()) / y + 0.12 * noise).clamp(0.005, 0.97)
+            });
+        }
+        assert!(fit_pairs(&sensor, &reference).is_some());
+    }
+
+    /// A camera that rotates saturated yellow-greens toward green (like Sony's "Standard" on a lime
+    /// shirt) can't be followed by a matrix alone: the fitted hue/saturation table must close most
+    /// of the gap, keep neutrals neutral and keep luminance.
+    #[test]
+    fn hue_table_follows_a_hue_dependent_camera_rendering() {
+        let to = to_prophoto();
+        let from = to.inverse().unwrap();
+        let mut sensor = Rgb32f::new(96, 64);
+        let mut reference = sensor.clone();
+        let mut lime = Vec::new();
+        for (i, (src, dst)) in sensor.data.iter_mut().zip(&mut reference.data).enumerate() {
+            let ev = 0.05 + (i % 29) as f32 * 0.02;
+            // mostly greys and mild colours, plus a patch of saturated yellow-green
+            *src = if i % 7 == 0 {
+                [ev * 0.75, ev, ev * 0.2]
+            } else {
+                [ev * (0.85 + (i % 11) as f32 * 0.03), ev, ev * (0.85 + (i % 13) as f32 * 0.025)]
+            };
+            let (h, s) = hue_saturation(to.apply(src.map(f64::from))).unwrap();
+            // the camera turns hues in 50°..110° (ProPhoto) by up to +15° and boosts their saturation
+            let k = (1.0 - ((h - 80.0) / 30.0).powi(2)).max(0.0) * s.min(1.0);
+            let mut p = to.apply(src.map(f64::from)).map(|v| v as f32);
+            let table = HsvTable {
+                hue_divisions: 1,
+                sat_divisions: 2,
+                val_divisions: 1,
+                data: vec![[0.0, 1.0, 1.0], [15.0 * k as f32, 1.0 + 0.3 * k as f32, 1.0]],
+                srgb_value: false,
+            };
+            p = table.apply(p);
+            let p = from.apply(p.map(f64::from)).map(|v| v as f32);
+            let scale = luminance_2020(*src) / luminance_2020(p);
+            let p = p.map(|v| v * scale);
+            let y = luminance_2020(p);
+            *dst = p.map(|v| v * (1.0 - (-2.5 * y).exp()) / y);
+            if i % 7 == 0 {
+                lime.push(i);
+            }
+        }
+        let fit = fit_pairs(&sensor, &reference).unwrap();
+        let table = fit.hue_sat.as_ref().expect("a hue/saturation table is fitted");
+        let hue_sat = HueSat::new(table).unwrap();
+        let hue_error = |with_table: bool| {
+            lime.iter()
+                .map(|&i| {
+                    let p = fit.matrix.apply(sensor.data[i].map(f64::from)).map(|v| v as f32);
+                    let p = if with_table { hue_sat.apply(p) } else { p };
+                    let (h, _) = hue_saturation(to.apply(p.map(f64::from))).unwrap();
+                    let (t, _) = hue_saturation(to.apply(reference.data[i].map(f64::from))).unwrap();
+                    ((h - t + 180.0).rem_euclid(360.0) - 180.0).abs()
+                })
+                .sum::<f64>()
+                / lime.len() as f64
+        };
+        let (before, after) = (hue_error(false), hue_error(true));
+        assert!(after < before * 0.5, "lime hue error {before:.2}° -> {after:.2}°");
+        // neutrals pass through and luminance is kept
+        let grey = [0.3, 0.3, 0.3];
+        assert!(hue_sat.apply(grey).iter().all(|v| (v - 0.3).abs() < 1e-4), "{:?}", hue_sat.apply(grey));
+        let green = [0.2, 0.4, 0.05];
+        assert!((luminance_2020(hue_sat.apply(green)) - luminance_2020(green)).abs() < 1e-5);
+    }
+
+    /// A camera that saturates shadows and bleaches highlights toward white (a per-channel curve),
+    /// which a luminance tone curve can't: the fitted chroma curve must follow it, so bright
+    /// warm-tinted rock renders white instead of cream.
+    #[test]
+    fn chroma_curve_follows_highlight_bleaching() {
+        let known = Mat3([[1.8, -0.4, -0.1], [-0.2, 1.5, -0.1], [-0.05, -0.3, 1.7]]);
+        let camera_chroma = |o: f32| 1.3 - 1.1 * o;
+        let mut sensor = Rgb32f::new(96, 64);
+        let mut reference = sensor.clone();
+        for (i, (src, dst)) in sensor.data.iter_mut().zip(&mut reference.data).enumerate() {
+            let ev = 0.02 + (i % 37) as f32 * 0.03;
+            *src = [ev * (0.75 + (i % 11) as f32 * 0.05), ev, ev * (0.7 + (i % 13) as f32 * 0.05)];
+            let p = known.apply_f32(*src);
+            let y = luminance_2020(p);
+            let o = 1.0 - (-2.5 * y).exp();
+            let k = camera_chroma(o);
+            *dst = p.map(|v| (o + (v * o / y - o) * k).clamp(0.0, 0.999));
+        }
+        let fit = fit_pairs(&sensor, &reference).unwrap();
+        // relative to the matrix, which already carries the average colourfulness
+        let chroma = fit.tone.chroma();
+        assert!(chroma[6] < 0.5 * chroma[1], "highlights bleach relative to shadows: {chroma:?}");
+        // and the rendered highlights land on the camera's, far closer than without the curve
+        let with = ToneMap::camera(&fit.tone, 0.0, 0.0, 0.0);
+        let without = ToneMap::camera(&fit.tone.with_chroma([1.0; lightcraft_pipeline::tone::CHROMA_N]).unwrap(), 0.0, 0.0, 0.0);
+        let highlight_error = |map: &ToneMap| -> f64 {
+            sensor
+                .data
+                .iter()
+                .zip(&reference.data)
+                .filter(|(_, y)| luminance_2020(**y) > 0.7)
+                .map(|(x, y)| {
+                    let p = displayed(fit.matrix.apply(x.map(f64::from)), map);
+                    (0..3).map(|c| (p[c] - f64::from(y[c])).powi(2)).sum::<f64>()
+                })
+                .sum()
+        };
+        let (a, b) = (highlight_error(&without), highlight_error(&with));
+        assert!(b < 0.5 * a, "highlight error {a:.4} -> {b:.4}");
+    }
+
+    /// Pooled pairs of several "photos" recover the camera's matrix, and a photo given that
+    /// colour model (a camera profile) keeps it, fitting only its own tone.
+    #[test]
+    fn profile_colour_is_pooled_and_then_used_as_given() {
+        let known = Mat3([[1.8, -0.4, -0.1], [-0.2, 1.5, -0.1], [-0.05, -0.3, 1.7]]);
+        let photo = |seed: usize, strength: f32| {
+            let mut sensor = Rgb32f::new(64, 48);
+            let mut reference = sensor.clone();
+            for (i, (src, dst)) in sensor.data.iter_mut().zip(&mut reference.data).enumerate() {
+                let i = i + seed * 7;
+                let ev = 0.04 + (i % 23) as f32 * 0.02;
+                *src = [ev * (0.7 + (i % 11) as f32 * 0.05), ev, ev * (0.7 + (i % 13) as f32 * 0.05)];
+                let p = known.apply_f32(*src);
+                let y = luminance_2020(p);
+                // each photo has its own tone (DRO, picture style)
+                *dst = p.map(|v| v * (1.0 - (-strength * y).exp()) / y);
+            }
+            (sensor, reference)
+        };
+        let mut pool = Vec::new();
+        for seed in 0..4 {
+            let (sensor, reference) = photo(seed, 2.0 + seed as f32 * 0.5);
+            pool.extend(collect_pairs(&sensor, &reference).unwrap().0);
+        }
+        let (matrix, _) = fit_profile(&pool).unwrap();
+        // the camera's colours (luminance-normalised: the tone curve sets brightness)
+        for x in [[0.8, 1.0, 0.75], [1.1, 1.0, 0.8], [0.75, 1.0, 1.2], [1.0; 3]] {
+            let (a, b) = (matrix.apply(x), known.apply(x));
+            let (la, lb) = (luma(a), luma(b));
+            assert!((0..3).all(|c| (a[c] / la - b[c] / lb).abs() < 0.01), "{x:?}: {a:?} vs {b:?}");
+        }
+        let (sensor, reference) = photo(9, 3.5);
+        let look = fit_pairs_with(&sensor, &reference, Some((matrix, None))).unwrap();
+        assert_eq!(look.matrix, matrix);
+        assert!(look.hue_sat.is_none());
+        let tone = ToneMap::camera(&look.tone, 0.0, 0.0, 0.0);
+        let error = sensor
+            .data
+            .iter()
+            .zip(&reference.data)
+            .map(|(x, y)| {
+                let p = displayed(look.matrix.apply(x.map(f64::from)), &tone);
+                (0..3).map(|c| (p[c] - f64::from(y[c])).powi(2)).sum::<f64>() / 3.0
+            })
+            .sum::<f64>()
+            / sensor.data.len() as f64;
+        assert!(error.sqrt() < 0.02, "this photo's own tone is followed: RMS {}", error.sqrt());
+    }
+
+    #[test]
+    fn hue_sat_passes_black_and_non_finite_pixels_through() {
+        let table = HsvTable { hue_divisions: 4, sat_divisions: 2, val_divisions: 1, data: vec![[10.0, 1.5, 1.0]; 8], srgb_value: false };
+        let hue_sat = HueSat::new(&table).unwrap();
+        assert_eq!(hue_sat.apply([0.0; 3]), [0.0; 3]);
+        let nan = hue_sat.apply([f32::NAN, 0.2, 0.1]);
+        assert!(nan[0].is_nan() && nan[1] == 0.2 && nan[2] == 0.1);
+        assert!(fit_hue_sat(&[], &Mat3::IDENTITY).is_none(), "too few samples");
+    }
+
+    #[test]
+    fn sony_and_nikon_raws_get_a_file_local_look() {
+        assert!([RawFormat::Arw, RawFormat::Nef, RawFormat::Nrw].into_iter().all(file_local_look));
+        assert!(![RawFormat::Dng, RawFormat::Cr2, RawFormat::Raf].into_iter().any(file_local_look));
+    }
+
+    /// A public D7500 NEF (skipped without the corpus): its look is fitted to its own JPEG and white
+    /// balance is relative to the as-shot look.
+    #[test]
+    fn corpus_nef_gets_a_camera_look() {
+        let path = std::env::var_os("LIGHTCRAFT_CORPUS")
+            .map(std::path::PathBuf::from)
+            .unwrap_or_else(|| std::path::Path::new(env!("CARGO_MANIFEST_DIR")).join("../../corpus"))
+            .join("raw/nef-nikon-d7500-lossless14.nef");
+        let Ok(bytes) = std::fs::read(&path) else {
+            eprintln!("skip: {} absent", path.display());
+            return;
+        };
+        let (_, info) = crate::files::load_bytes(&bytes, 400).unwrap();
+        assert!(info.camera_tone.is_some(), "no camera look fitted");
+        assert!(info.relative_wb && info.as_shot_temp == 6500.0 && info.as_shot_tint == 0.0);
+    }
+
+    #[test]
+    fn rejects_monochrome_invalid_and_unrelated_previews() {
+        let mut sensor = Rgb32f::new(32, 32);
+        let mut reference = sensor.clone();
+        for (i, p) in sensor.data.iter_mut().enumerate() {
+            *p = [0.1 + (i % 13) as f32 * 0.02, 0.15, 0.1];
+        }
+        reference.data.fill([0.2; 3]);
+        assert!(fit_pairs(&sensor, &reference).is_none());
+        reference.data.fill([f32::NAN; 3]);
+        assert!(fit_pairs(&sensor, &reference).is_none());
+        for (i, (src, dst)) in sensor.data.iter_mut().zip(&mut reference.data).enumerate() {
+            *src = [0.04 + (i % 11) as f32 * 0.02, 0.05 + (i % 17) as f32 * 0.01, 0.03 + (i % 23) as f32 * 0.01];
+            *dst = [0.05 + (i % 7) as f32 * 0.07, 0.05 + (i % 19) as f32 * 0.02, 0.05 + (i % 29) as f32 * 0.01];
+        }
+        assert!(fit_pairs(&sensor, &reference).is_none());
+        sensor.data.fill([0.1, 0.15, 0.12]);
+        assert!(fit_pairs(&sensor, &reference).is_none());
+        reference.data.truncate(8);
+        assert!(fit_pairs(&sensor, &reference).is_none());
+    }
+}

crates/engine/src/camera_profiles.rs

@@ -0,0 +1,310 @@
+//! Camera colour profiles of our own, pooled from many photos of one camera model.
+//!
+//! A raw file without colour matrices (Sony ARW, Nikon NEF) gets its look fitted to its own embedded camera
+//! JPEG (`camera_preview`), but one photo shows too little of some colours: a lime shirt covering a
+//! few dozen proxy pixels next to a hillside of foliage at the same hue. `lightcraft-cli calibrate`
+//! pools the colour pairs of many photos per model and fits one matrix and hue/saturation/value
+//! table; photos of that model then only fit their tone and chroma curves.
+//!
+//! Profiles are JSON files (`<model>.json`) in [`dir`]: `LIGHTCRAFT_CAMERA_PROFILES`, else
+//! `<config>/camera-profiles`; a local profile replaces the one built in ([`BUNDLED`], from
+//! `assets/camera-profiles/`). They are read once per process; a damaged or hostile file is
+//! ignored with a warning. They hold aggregate colour statistics only, never image content.
+use lightcraft_color::Mat3;
+use lightcraft_raw::profile::HsvTable;
+use serde::{Deserialize, Serialize};
+use std::collections::HashMap;
+use std::path::{Path, PathBuf};
+use std::sync::{Arc, Mutex, OnceLock, PoisonError};
+
+/// Format version of the profile files.
+const VERSION: u32 = 1;
+/// Largest profile file read (a 5 × 72 × 5 table is ~60 KB of JSON).
+const MAX_FILE: u64 = 4 << 20;
+
+/// Profiles built into LightCraft (`assets/camera-profiles/`, see `assets/ATTRIBUTION.md`):
+/// `(model, JSON)`.
+pub const BUNDLED: &[(&str, &str)] = &[("ILCE-7M4", include_str!("../../../assets/camera-profiles/ILCE-7M4.json"))];
+
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
+pub struct CameraProfile {
+    pub version: u32,
+    /// The camera model as the files report it (Exif `Model`), e.g. `ILCE-7M4`.
+    pub model: String,
+    /// Photos and colour pairs the profile was fitted on.
+    pub files: usize,
+    pub samples: usize,
+    /// White-balanced camera RGB (with the baseline exposure) → linear Rec.2020, rows.
+    matrix: [[f64; 3]; 3],
+    /// Hue/saturation/value correction after `matrix` (linear ProPhoto RGB).
+    pub hue_sat: Option<HsvTable>,
+}
+
+impl CameraProfile {
+    pub fn new(model: &str, files: usize, samples: usize, matrix: Mat3, hue_sat: Option<HsvTable>) -> CameraProfile {
+        CameraProfile { version: VERSION, model: model.to_owned(), files, samples, matrix: matrix.0, hue_sat }
+    }
+
+    pub fn matrix(&self) -> Mat3 {
+        Mat3(self.matrix)
+    }
+
+    /// Whether the data is usable (bounded matrix, table shape matching its data).
+    fn valid(&self) -> bool {
+        let matrix = self.matrix.iter().flatten().all(|v| v.is_finite() && v.abs() < 8.0) && Mat3(self.matrix).inverse().is_some();
+        let table = self.hue_sat.as_ref().is_none_or(|t| {
+            let dims = (1..=4096).contains(&t.hue_divisions) && (2..=4096).contains(&t.sat_divisions) && (1..=4096).contains(&t.val_divisions);
+            let len = t.hue_divisions.checked_mul(t.sat_divisions).and_then(|n| n.checked_mul(t.val_divisions));
+            dims && len == Some(t.data.len()) && t.data.iter().flatten().all(|v| v.is_finite()) && t.data.iter().all(|e| e[1] >= 0.0 && e[2] >= 0.0)
+        });
+        self.version == VERSION && !self.model.is_empty() && matrix && table
+    }
+}
+
+/// LightCraft's configuration folder (settings, GPU marker, camera profiles).
+pub fn config_dir() -> Option<PathBuf> {
+    if cfg!(target_os = "macos") {
+        std::env::var_os("HOME").map(|h| PathBuf::from(h).join("Library/Application Support/LightCraft"))
+    } else if cfg!(windows) {
+        std::env::var_os("APPDATA").map(|a| PathBuf::from(a).join("LightCraft"))
+    } else {
+        std::env::var_os("XDG_CONFIG_HOME")
+            .map(PathBuf::from)
+            .or_else(|| std::env::var_os("HOME").map(|h| PathBuf::from(h).join(".config")))
+            .map(|c| c.join("lightcraft"))
+    }
+}
+
+/// Where camera profiles are read from and written to.
+pub fn dir() -> Option<PathBuf> {
+    std::env::var_os("LIGHTCRAFT_CAMERA_PROFILES").map(PathBuf::from).or_else(|| config_dir().map(|d| d.join("camera-profiles")))
+}
+
+/// File name of `model`'s profile: letters, digits, `-` and `_` kept, anything else `_`.
+pub fn file_name(model: &str) -> String {
+    let name: String = model.trim().chars().map(|c| if c.is_ascii_alphanumeric() || c == '-' || c == '_' { c } else { '_' }).collect();
+    format!("{name}.json")
+}
+
+/// Read and validate a profile file.
+pub fn load(path: &Path) -> Result<CameraProfile, String> {
+    let size = std::fs::metadata(path).map_err(|e| format!("{}: {e}", path.display()))?.len();
+    if size > MAX_FILE {
+        return Err(format!("{}: {size} bytes is too large for a camera profile", path.display()));
+    }
+    let bytes = std::fs::read(path).map_err(|e| format!("{}: {e}", path.display()))?;
+    parse(&bytes, &path.display().to_string())
+}
+
+/// Parse and validate a profile's JSON (`origin` names it in errors).
+fn parse(json: &[u8], origin: &str) -> Result<CameraProfile, String> {
+    let profile: CameraProfile = serde_json::from_slice(json).map_err(|e| format!("{origin}: {e}"))?;
+    if !profile.valid() {
+        return Err(format!("{origin}: not a usable camera profile (version {}, model {:?})", profile.version, profile.model));
+    }
+    Ok(profile)
+}
+
+/// The built-in profile for `model`, if any.
+fn bundled(model: &str) -> Option<CameraProfile> {
+    let (_, json) = BUNDLED.iter().find(|(m, _)| *m == model)?;
+    parse(json.as_bytes(), &format!("built-in profile {model}")).inspect_err(|e| eprintln!("lightcraft: ignoring camera profile {e}")).ok()
+}
+
+/// Write `profile` to `dir` (created if needed) as `<model>.json`; returns the path.
+pub fn save(profile: &CameraProfile, dir: &Path) -> Result<PathBuf, String> {
+    std::fs::create_dir_all(dir).map_err(|e| format!("{}: {e}", dir.display()))?;
+    let path = dir.join(file_name(&profile.model));
+    let json = serde_json::to_vec_pretty(profile).map_err(|e| e.to_string())?;
+    let tmp = path.with_extension("json.tmp");
+    std::fs::write(&tmp, json).map_err(|e| format!("{}: {e}", tmp.display()))?;
+    std::fs::rename(&tmp, &path).map_err(|e| format!("{}: {e}", path.display()))?;
+    Ok(path)
+}
+
+fn cache() -> &'static Mutex<HashMap<String, Option<Arc<CameraProfile>>>> {
+    static CACHE: OnceLock<Mutex<HashMap<String, Option<Arc<CameraProfile>>>>> = OnceLock::new();
+    CACHE.get_or_init(Default::default)
+}
+
+/// The profile for camera `model`: from [`dir`], else built in; read once per process.
+pub fn get(model: &str) -> Option<Arc<CameraProfile>> {
+    let model = model.trim();
+    if model.is_empty() {
+        return None;
+    }
+    let mut cache = cache().lock().unwrap_or_else(PoisonError::into_inner);
+    if let Some(hit) = cache.get(model) {
+        return hit.clone();
+    }
+    let path = dir().map(|d| d.join(file_name(model)));
+    let profile = match path {
+        Some(path) if path.is_file() => match load(&path) {
+            Ok(p) if p.model.trim() == model => Some(Arc::new(p)),
+            Ok(p) => {
+                eprintln!("lightcraft: ignoring camera profile {}: it is for {:?}, not {model:?}", path.display(), p.model);
+                None
+            }
+            Err(e) => {
+                eprintln!("lightcraft: ignoring camera profile {e}");
+                None
+            }
+        },
+        _ => None,
+    };
+    let profile = profile.or_else(|| bundled(model).map(Arc::new));
+    cache.insert(model.to_owned(), profile.clone());
+    profile
+}
+
+/// Changes when the profiles folder's contents change (per process): part of the render cache
+/// keys, so thumbnails rendered before a profile existed are not reused after.
+pub fn cache_key() -> u64 {
+    static KEY: OnceLock<u64> = OnceLock::new();
+    *KEY.get_or_init(|| {
+        let entries = dir().and_then(|d| std::fs::read_dir(d).ok());
+        let mut files: Vec<(String, u64, u64)> = entries
+            .into_iter()
+            .flatten()
+            .flatten()
+            .filter(|e| e.path().extension().is_some_and(|x| x == "json"))
+            .filter_map(|e| {
+                let meta = e.metadata().ok()?;
+                let modified = meta.modified().ok()?.duration_since(std::time::UNIX_EPOCH).ok()?.as_secs();
+                Some((e.file_name().to_string_lossy().into_owned(), meta.len(), modified))
+            })
+            .collect();
+        files.sort();
+        let mut h = lightcraft_preview::Hasher128::new();
+        for (name, len, modified) in &files {
+            h.str(name).u64(*len).u64(*modified);
+        }
+        for (model, json) in BUNDLED {
+            h.str(model).str(json);
+        }
+        h.finish().0 as u64
+    })
+}
+
+/// Per camera model: the photos read and their pooled colour pairs.
+#[derive(Default)]
+pub struct Pool {
+    models: HashMap<String, (usize, Vec<([f64; 3], [f64; 3])>)>,
+}
+
+/// Most colour pairs kept per photo, so a few busy photos can't dominate a profile.
+const PAIRS_PER_FILE: usize = 4000;
+
+impl Pool {
+    /// Add one raw file's colour pairs. `Ok(None)` when the file can't contribute (not an ARW or
+    /// NEF without colour matrices, no usable camera JPEG, too little colour).
+    pub fn add(&mut self, bytes: &[u8]) -> Result<Option<String>, String> {
+        let raw = lightcraft_raw::decode(bytes).map_err(|e| e.to_string())?;
+        let Some(model) = raw.metadata.model.as_deref().map(str::trim).filter(|m| !m.is_empty()) else { return Ok(None) };
+        let Some(pairs) = crate::camera_preview::profile_pairs(&raw, bytes) else { return Ok(None) };
+        let step = pairs.len().div_ceil(PAIRS_PER_FILE).max(1);
+        let entry = self.models.entry(model.to_owned()).or_default();
+        entry.0 += 1;
+        entry.1.extend(pairs.into_iter().step_by(step));
+        Ok(Some(model.to_owned()))
+    }
+
+    /// Fit a profile per model with at least `min_files` photos.
+    pub fn fit(&self, min_files: usize) -> Vec<Result<CameraProfile, String>> {
+        let mut models: Vec<_> = self.models.iter().collect();
+        models.sort_by(|a, b| a.0.cmp(b.0));
+        models
+            .into_iter()
+            .filter(|(_, (files, _))| *files >= min_files)
+            .map(|(model, (files, pairs))| {
+                let (matrix, hue_sat) = crate::camera_preview::fit_profile(pairs).ok_or_else(|| format!("{model}: no usable colour fit"))?;
+                Ok(CameraProfile::new(model, *files, pairs.len(), matrix, hue_sat))
+            })
+            .collect()
+    }
+
+    /// Add another pool's photos and pairs (pools filled on separate threads).
+    pub fn merge(&mut self, other: Pool) {
+        for (model, (files, pairs)) in other.models {
+            let entry = self.models.entry(model).or_default();
+            entry.0 += files;
+            entry.1.extend(pairs);
+        }
+    }
+
+    /// Photos read per model.
+    pub fn files(&self) -> Vec<(String, usize)> {
+        let mut v: Vec<_> = self.models.iter().map(|(m, (n, _))| (m.clone(), *n)).collect();
+        v.sort();
+        v
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn profile() -> CameraProfile {
+        let table = HsvTable { hue_divisions: 4, sat_divisions: 2, val_divisions: 1, data: vec![[5.0, 1.2, 1.0]; 8], srgb_value: false };
+        CameraProfile::new("ILCE-7M4", 12, 3456, Mat3([[1.6, -0.5, -0.1], [-0.2, 1.3, -0.1], [-0.1, -0.2, 1.3]]), Some(table))
+    }
+
+    #[test]
+    fn profiles_round_trip_and_reject_bad_files() {
+        let dir = std::env::temp_dir().join(format!("lc-camera-profiles-{}", std::process::id()));
+        let path = save(&profile(), &dir).unwrap();
+        assert_eq!(path.file_name().unwrap(), "ILCE-7M4.json");
+        assert_eq!(load(&path).unwrap(), profile());
+        let bad = |p: CameraProfile| {
+            let path = dir.join("bad.json");
+            std::fs::write(&path, serde_json::to_vec(&p).unwrap()).unwrap();
+            load(&path).is_err()
+        };
+        let mut p = profile();
+        p.matrix[0][0] = f64::NAN;
+        assert!(bad(p), "non-finite matrix");
+        let mut p = profile();
+        p.matrix = [[0.0; 3]; 3];
+        assert!(bad(p), "singular matrix");
+        let mut p = profile();
+        if let Some(t) = p.hue_sat.as_mut() {
+            t.data.truncate(3);
+        }
+        assert!(bad(p), "table data doesn't match its shape");
+        let mut p = profile();
+        p.version = 99;
+        assert!(bad(p), "unknown version");
+        std::fs::write(dir.join("junk.json"), b"{not json").unwrap();
+        assert!(load(&dir.join("junk.json")).is_err());
+        assert!(load(&dir.join("missing.json")).is_err());
+        let _ = std::fs::remove_dir_all(&dir);
+    }
+
+    #[test]
+    fn bundled_profiles_are_valid_and_named_after_their_model() {
+        assert!(!BUNDLED.is_empty());
+        for (model, json) in BUNDLED {
+            let p = parse(json.as_bytes(), model).unwrap();
+            assert_eq!(p.model, *model);
+            assert!(p.files >= 5 && p.hue_sat.is_some(), "{model}: {} photos", p.files);
+            assert_eq!(bundled(model), Some(p));
+        }
+        assert!(bundled("No Such Camera").is_none());
+    }
+
+    #[test]
+    fn file_names_are_safe() {
+        assert_eq!(file_name("ILCE-7M4"), "ILCE-7M4.json");
+        assert_eq!(file_name(" DSC-RX100M3 "), "DSC-RX100M3.json");
+        assert_eq!(file_name("../../etc/passwd"), "______etc_passwd.json");
+        assert_eq!(file_name("Ω 1/2"), "__1_2.json");
+    }
+
+    #[test]
+    fn pool_skips_files_that_cannot_contribute() {
+        let mut pool = Pool::default();
+        assert!(pool.add(b"not a raw file").is_err());
+        assert!(pool.fit(1).is_empty());
+        assert!(pool.files().is_empty());
+    }
+}

crates/engine/src/cmd/color.rs

@@ -26,7 +26,7 @@ const PROBE_EDGE: usize = 384;
 pub(crate) fn probe(s: &mut Session, c: &str, x: f64, y: f64, neutral: impl FnOnce(&mut DevelopSettings)) -> Result<[f32; 3]> {
     let id = s.active().ok_or_else(|| bad(c, "no active photo"))?;
     let src = s.source_now(id, SourceLevel::Thumb).map_err(|e| bad(c, e))?;
-    let info = s.catalog.photo(id).map(|p| crate::media::source_info(p)).unwrap_or_default();
+    let info = s.source_info(id);
     let mut d = (*s.develop_of(id).unwrap_or_default()).clone();
     neutral(&mut d);
     let req = lightcraft_pipeline::RenderRequest::fit(PROBE_EDGE, PROBE_EDGE);

crates/engine/src/cmd/convert.rs

@@ -26,7 +26,12 @@ fn dng_names(path: &str) -> impl Iterator<Item = std::path::PathBuf> {
 /// written to a temp file, synced, read back identical and only then given its name — never
 /// replacing an existing file. On any failure no DNG is left behind and the raw stays in use.
 pub(crate) fn write_dng_for(s: &Session, path: &str, packet: String) -> std::result::Result<String, String> {
-    let bytes = match &s.media.file_bytes {
+    write_dng_with(s.media.file_bytes.as_ref(), path, packet)
+}
+
+/// [`write_dng_for`] without the session (imports convert on a worker thread).
+pub(crate) fn write_dng_with(file_bytes: Option<&crate::merge::ByteReader>, path: &str, packet: String) -> std::result::Result<String, String> {
+    let bytes = match file_bytes {
         Some(r) => r(path)?,
         None => std::fs::read(path).map_err(|e| format!("{path}: {e}"))?,
     };
@@ -144,7 +149,8 @@ fn edit_external(s: &mut Session, p: &Value) -> Result<Value> {
     };
     let mut written = Vec::new();
     let mut write = |path: &str, bytes: &[u8]| -> std::result::Result<(), String> {
-        crate::export::write_file(path, bytes)?;
+        // durable: the TIFF becomes a library photo the external editor then changes
+        crate::export::write_file_durable(path, bytes)?;
         written.push(path.to_string());
         Ok(())
     };
@@ -177,6 +183,33 @@ pub(crate) fn content_op(id: lightcraft_catalog::PhotoId, ph: &lightcraft_catalo
     })
 }
 
+/// Ops that fill a photo's empty camera fields (camera, lens, exposure, GPS, capture time) from a fresh probe.
+fn fill_missing_meta(id: lightcraft_catalog::PhotoId, ph: &lightcraft_catalog::Photo, info: &crate::media::ProbeInfo) -> Vec<Op> {
+    let (mut m, src) = (ph.meta.clone(), &info.meta);
+    let before = m.clone();
+    if m.camera.is_empty() {
+        m.camera = src.camera.clone();
+    }
+    if m.lens.is_empty() {
+        m.lens = src.lens.clone();
+    }
+    if m.shutter.is_empty() {
+        m.shutter = src.shutter.clone();
+    }
+    m.focal_mm = m.focal_mm.or(src.focal_mm);
+    m.aperture = m.aperture.or(src.aperture);
+    m.iso = m.iso.or(src.iso);
+    m.gps = m.gps.or(src.gps);
+    let mut ops = Vec::new();
+    if m != before {
+        ops.push(Op::SetMeta { id, meta: Box::new(m) });
+    }
+    if ph.captured.is_none() && info.captured.is_some() {
+        ops.push(Op::SetCaptured { id, captured: info.captured.clone() });
+    }
+    ops
+}
+
 /// Re-read photos whose files changed on disk (an external editor saved them): new size,
 /// dimensions and content hash, cached sources dropped. → {reloaded: [ids]}
 fn reload(s: &mut Session, p: &Value) -> Result<Value> {
@@ -193,8 +226,18 @@ fn reload(s: &mut Session, p: &Value) -> Result<Value> {
     let mut reloaded = Vec::new();
     for ((id, _), info) in paths.into_iter().zip(probed) {
         let (Ok(info), Some(ph)) = (info, s.catalog.photo(id)) else { continue };
-        let Some(op) = content_op(id, ph, info.clone()) else { continue };
+        // camera fields the catalog lacks (e.g. a raw imported before its format was read) are filled in;
+        // nothing already set is overwritten
+        let meta_ops = fill_missing_meta(id, ph, &info);
+        let Some(op) = content_op(id, ph, info.clone()) else {
+            if !meta_ops.is_empty() {
+                ops.extend(meta_ops);
+                reloaded.push(id);
+            }
+            continue;
+        };
         ops.push(op);
+        ops.extend(meta_ops);
         // virtual copies share the file
         for c in s.catalog.photos().filter(|c| c.copy_of == Some(id)) {
             ops.extend(content_op(c.id, c, info.clone()));
@@ -271,9 +314,9 @@ pub fn edit_specs() -> Vec<CommandSpec> {
         cmd!(
             "photo.reload",
             "Reload from Disk",
-            [],
+            ["Photo"],
             None,
-            "{ids?} — re-read photos whose files changed on disk (e.g. saved by an external editor), or raws shown from their embedded preview that can be decoded now → {reloaded}",
+            "{ids?} — re-read photos whose files changed on disk (e.g. saved by an external editor), or raws shown from their embedded preview that can be decoded now; camera fields the catalog lacks are filled in → {reloaded}",
             has_selection,
             reload
         ),
@@ -288,3 +331,32 @@ pub fn edit_specs() -> Vec<CommandSpec> {
         ),
     ]
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use lightcraft_catalog::{Photo, PhotoId, Source};
+
+    /// Reload fills camera fields a photo lacks (a CR3 imported before CR3 metadata was read) and keeps
+    /// everything already set.
+    #[test]
+    fn reload_fills_only_missing_camera_fields() {
+        let mut ph = Photo::new(PhotoId(1), Source::File { path: "/x.cr3".into() }, "x.cr3", "CR3", 1620, 1080, "2026-10-06T00:00:00");
+        ph.meta.title = "Mine".into();
+        ph.meta.iso = Some(800);
+        let mut info = crate::media::ProbeInfo { captured: Some("2026-10-04T08:16:11".into()), ..Default::default() };
+        info.meta.camera = "Canon EOS R6 Mark III".into();
+        info.meta.lens = "RF24-105mm".into();
+        info.meta.iso = Some(400);
+        info.meta.aperture = Some(6.3);
+        let ops = fill_missing_meta(PhotoId(1), &ph, &info);
+        let Some(Op::SetMeta { meta, .. }) = ops.first() else { panic!("{ops:?}") };
+        assert_eq!((meta.camera.as_str(), meta.lens.as_str(), meta.aperture), ("Canon EOS R6 Mark III", "RF24-105mm", Some(6.3)));
+        assert_eq!((meta.title.as_str(), meta.iso), ("Mine", Some(800)), "set fields are kept");
+        assert!(matches!(ops.get(1), Some(Op::SetCaptured { captured: Some(_), .. })));
+        // nothing missing → nothing to do
+        ph.meta = (**meta).clone();
+        ph.captured = Some("2026-10-04T08:16:11".into());
+        assert!(fill_missing_meta(PhotoId(1), &ph, &info).is_empty());
+    }
+}

crates/engine/src/cmd/develop.rs

@@ -98,7 +98,11 @@ pub fn specs() -> Vec<CommandSpec> {
                     }
                 }
                 let label = if vals.len() == 1 { controls::find(&vals[0].0).map(|c| c.label).unwrap_or("Edit").to_string() } else { "Edit".into() };
-                let apply = |d: &mut DevelopSettings| {
+                let apply = |d: &mut DevelopSettings, info: &lightcraft_pipeline::SourceInfo| {
+                    if d.wb.mode == WbMode::AsShot && vals.iter().any(|(k, _)| k == "wb.temp" || k == "wb.tint") {
+                        d.wb.temp = info.as_shot_temp;
+                        d.wb.tint = info.as_shot_tint;
+                    }
                     for (k, v) in &vals {
                         controls::set(d, k, *v);
                         if k == "wb.temp" || k == "wb.tint" {
@@ -113,15 +117,18 @@ pub fn specs() -> Vec<CommandSpec> {
                         .filter_map(|id| s.develop_of(*id).map(|d| (*id, d)))
                         .filter_map(|(id, d)| {
                             let mut d = (*d).clone();
-                            apply(&mut d);
+                            let info = s.source_info(id);
+                            apply(&mut d, &info);
                             s.develop_op(id, d, &label)
                         })
                         .collect();
                     s.commit(&label, Op::Batch { ops })?;
                     return ok();
                 }
+                let id = active(s, "develop.set")?;
+                let info = s.source_info(id);
                 edit(s, "develop.set", &label, |d| {
-                    apply(d);
+                    apply(d, &info);
                     Ok(())
                 })
             }
@@ -130,7 +137,15 @@ pub fn specs() -> Vec<CommandSpec> {
             let c = str_param(p, "control").ok_or_else(|| bad("develop.adjust", "missing control"))?.to_string();
             let spec = controls::find(&c).ok_or_else(|| bad("develop.adjust", "unknown control"))?;
             let delta = f64_req(p, "delta", "develop.adjust")?;
+            let info = s.source_info(active(s, "develop.adjust")?);
             edit(s, "develop.adjust", spec.label, |d| {
+                if c == "wb.temp" || c == "wb.tint" {
+                    if d.wb.mode == WbMode::AsShot {
+                        d.wb.temp = info.as_shot_temp;
+                        d.wb.tint = info.as_shot_tint;
+                    }
+                    d.wb.mode = WbMode::Custom;
+                }
                 let v = controls::get(d, &c).unwrap_or(spec.default);
                 controls::set(d, &c, v + delta);
                 Ok(())
@@ -149,12 +164,18 @@ pub fn specs() -> Vec<CommandSpec> {
             let ops = ids
                 .iter()
                 .filter_map(|id| s.develop_of(*id).map(|d| (*id, d)))
-                .filter_map(|(id, d)| {
+                .filter_map(|(id, _d)| {
                     // back to the photo's import defaults when a default preset gave it its look
                     let look = s.catalog.photo(id).and_then(|p| p.import_look.clone());
                     let fresh = match look {
                         Some(l) => (*l).clone(),
-                        None => DevelopSettings { wb: lightcraft_develop::WhiteBalance { mode: WbMode::AsShot, ..d.wb }, ..Default::default() },
+                        None => {
+                            let info = s.source_info(id);
+                            DevelopSettings {
+                                wb: lightcraft_develop::WhiteBalance { mode: WbMode::AsShot, temp: info.as_shot_temp, tint: info.as_shot_tint },
+                                ..Default::default()
+                            }
+                        }
                     };
                     s.develop_op(id, fresh, "Reset")
                 })
@@ -203,7 +224,7 @@ pub fn specs() -> Vec<CommandSpec> {
             |s, _| {
                 let id = active(s, "develop.autoBwMix")?;
                 let src = s.source_now(id, SourceLevel::Thumb).map_err(|e| bad("develop.autoBwMix", e))?;
-                let info = s.catalog.photo(id).map(|p| crate::media::source_info(p)).unwrap_or_default();
+                let info = s.source_info(id);
                 let d = s.develop_of(id).unwrap_or_default();
                 let m = lightcraft_pipeline::auto::auto_bw_mix(&src, &info, &d);
                 edit(s, "develop.autoBwMix", "Auto B&W Mix", |d| {
@@ -218,7 +239,7 @@ pub fn specs() -> Vec<CommandSpec> {
         cmd!("develop.auto", "Auto Settings", ["Photo"], Some("Shift+A"), "{}", has_active, |s, _| {
             let id = active(s, "develop.auto")?;
             let src = s.source_now(id, SourceLevel::Thumb).map_err(|e| bad("develop.auto", e))?;
-            let info = s.catalog.photo(id).map(|p| crate::media::source_info(p)).unwrap_or_default();
+            let info = s.source_info(id);
             let d = s.develop_of(id).unwrap_or_default();
             let a = lightcraft_pipeline::auto::auto_tone(&src, &info, &d);
             edit(s, "develop.auto", "Auto", |d| {
@@ -245,7 +266,7 @@ pub fn specs() -> Vec<CommandSpec> {
                 let mode: WbMode =
                     serde_json::from_value(p.get("mode").cloned().unwrap_or(json!("custom"))).map_err(|e| bad("develop.wb", e.to_string()))?;
                 let id = active(s, "develop.wb")?;
-                let info = s.catalog.photo(id).map(|p| crate::media::source_info(p)).unwrap_or_default();
+                let info = s.source_info(id);
                 let (mut t, mut tint) = match mode {
                     WbMode::AsShot => (info.as_shot_temp, info.as_shot_tint),
                     WbMode::Auto => {
@@ -256,7 +277,7 @@ pub fn specs() -> Vec<CommandSpec> {
                         .preset()
                         .map(|(t, ti)| {
                             // presets are relative to daylight for rendered files
-                            if info.raw { (t, ti) } else { (6500.0 * t / 5500.0, ti) }
+                            if info.raw && !info.relative_wb { (t, ti) } else { (6500.0 * t / 5500.0, ti) }
                         })
                         .unwrap_or((info.as_shot_temp, info.as_shot_tint)),
                 };
@@ -277,7 +298,7 @@ pub fn specs() -> Vec<CommandSpec> {
             let (x, y) = (f64_req(p, "x", "develop.wbPick")?, f64_req(p, "y", "develop.wbPick")?);
             let id = active(s, "develop.wbPick")?;
             let src = s.source_now(id, SourceLevel::Thumb).map_err(|e| bad("develop.wbPick", e))?;
-            let info = s.catalog.photo(id).map(|p| crate::media::source_info(p)).unwrap_or_default();
+            let info = s.source_info(id);
             let d = s.develop_of(id).unwrap_or_default();
             // Sample a small neighbourhood in the oriented source.
             let o = src.oriented(d.orientation);
@@ -405,7 +426,7 @@ pub fn specs() -> Vec<CommandSpec> {
             |s, _| {
                 let id = active(s, "crop.autoStraighten")?;
                 let src = s.source_now(id, SourceLevel::Preview).map_err(|e| bad("crop.autoStraighten", e))?;
-                let info = s.catalog.photo(id).map(|p| crate::media::source_info(p)).unwrap_or_default();
+                let info = s.source_info(id);
                 let d = s.develop_of(id).unwrap_or_default();
                 let Some(level) = lightcraft_pipeline::upright::level_degrees(&src, &info, &d) else {
                     return Ok(json!({"changed": false, "reason": "no dominant horizontal or vertical lines"}));
@@ -501,7 +522,7 @@ pub fn specs() -> Vec<CommandSpec> {
                     Upright::Off | Upright::Guided => None,
                     m => {
                         let src = s.source_now(id, SourceLevel::Preview).map_err(|e| bad("geometry.upright", e))?;
-                        let info = s.catalog.photo(id).map(|p| crate::media::source_info(p)).unwrap_or_default();
+                        let info = s.source_info(id);
                         Some(lightcraft_pipeline::upright::auto_transform(&src, &info, &d, m))
                     }
                 };
@@ -657,6 +678,11 @@ pub fn specs() -> Vec<CommandSpec> {
                     .filter_map(|id| s.develop_of(id).map(|d| (id, d)))
                     .filter_map(|(id, d)| {
                         let mut nd = (*d).clone();
+                        if nd.wb.mode == WbMode::AsShot && (ctl == "wb.temp" || ctl == "wb.tint") {
+                            let info = s.source_info(id);
+                            nd.wb.temp = info.as_shot_temp;
+                            nd.wb.tint = info.as_shot_tint;
+                        }
                         let v = controls::get(&nd, &ctl).unwrap_or(spec.default);
                         controls::set(&mut nd, &ctl, v + delta);
                         if ctl == "wb.temp" || ctl == "wb.tint" {

crates/engine/src/cmd/library.rs

@@ -7,6 +7,105 @@ use serde_json::{Value, json};
 use super::{CommandSpec, always, bad, bool_or, cmd, has_active, has_selection, ok, str_param};
 use crate::{LibrarySource, Result, Selection, Session};
 
+/// The auto-import folder's visible files with their sizes (the file-system half of
+/// `library.autoImportScan`; the app lists on a worker thread and passes `listing`).
+pub fn list_auto_import_folder(folder: &str) -> std::result::Result<Vec<(String, u64)>, String> {
+    let rd = std::fs::read_dir(folder).map_err(|e| format!("{folder}: {e}"))?;
+    Ok(rd
+        .flatten()
+        .filter(|e| !e.file_name().to_string_lossy().starts_with('.'))
+        .filter_map(|e| {
+            let m = std::fs::metadata(e.path()).ok()?;
+            m.is_file().then(|| (e.path().to_string_lossy().to_string(), m.len()))
+        })
+        .collect())
+}
+
+/// `library.import`'s params, checked (no file-system calls).
+pub struct ImportRequest {
+    pub paths: Vec<String>,
+    pub opts: crate::import::ImportOptions,
+    pub album: Option<u64>,
+    pub album_name: Option<String>,
+}
+
+/// Parse and check `library.import`'s params (the app's import task runs the import itself, on a
+/// worker thread, with the same options).
+pub fn import_params(s: &Session, p: &Value) -> Result<ImportRequest> {
+    let paths = strs(p, "paths");
+    let mode = match str_param(p, "mode").unwrap_or("add") {
+        "add" => crate::import::ImportMode::Add,
+        "copy" => crate::import::ImportMode::Copy,
+        "move" => crate::import::ImportMode::Move,
+        other => return Err(bad("library.import", format!("unknown mode `{other}` (add|copy|move)"))),
+    };
+    let preset = match str_param(p, "preset").filter(|x| !x.is_empty()) {
+        Some(id) => Some(s.presets.iter().find(|x| x.id == id).cloned().ok_or_else(|| bad("library.import", format!("unknown preset `{id}`")))?),
+        None => None,
+    };
+    let album = p.get("album").and_then(Value::as_u64);
+    if let Some(a) = album
+        && s.catalog.album(AlbumId(a)).is_none_or(|al| al.folder || al.is_smart())
+    {
+        return Err(bad("library.import", "album must be a regular album"));
+    }
+    let organize = match str_param(p, "organize") {
+        Some(o) => crate::import::Organize::parse(o).ok_or_else(|| {
+            bad("library.import", format!("unknown organize `{o}` (date|month|flat, or a folder template like {{date:%Y}}/{{date:%Y%m%d}})"))
+        })?,
+        None => Default::default(),
+    };
+    if let crate::import::Organize::Template(t) = &organize
+        && let Some(e) = crate::rename::folder_template_error(t)
+    {
+        return Err(bad("library.import", e));
+    }
+    let metadata_preset = str_param(p, "metadataPreset").map(str::trim).filter(|n| !n.is_empty()).map(str::to_string);
+    if let Some(n) = &metadata_preset
+        && !s.metadata_presets.iter().any(|m| m.name.eq_ignore_ascii_case(n))
+    {
+        return Err(bad("library.import", format!("unknown metadata preset `{n}`")));
+    }
+    let opts = crate::import::ImportOptions {
+        mode,
+        preset,
+        keywords: strs(p, "keywords"),
+        destination: str_param(p, "destination").map(str::to_string),
+        organize,
+        rename: str_param(p, "rename").map(str::to_string),
+        rename_start: p.get("renameStart").and_then(Value::as_u64).unwrap_or(1) as usize,
+        metadata_preset,
+        convert_dng: bool_or(p, "dng", false),
+        local: bool_or(p, "local", false),
+    };
+    let album_name = str_param(p, "albumName").map(str::trim).filter(|n| !n.is_empty()).map(str::to_string);
+    Ok(ImportRequest { paths, opts, album, album_name })
+}
+
+/// After a batch of an import was committed: the album (a new one named `album_name` when there
+/// is no `album` and something was imported) gets the photos. Returns the report as JSON (with
+/// `album`).
+pub fn import_batch_done(s: &mut Session, report: crate::import::ImportReport, mut album: Option<u64>, album_name: Option<&str>) -> Result<Value> {
+    let mut report = serde_json::to_value(report).unwrap_or_default();
+    let imported: Vec<u64> = report["imported"].as_array().map(|a| a.iter().filter_map(Value::as_u64).collect()).unwrap_or_default();
+    if album.is_none()
+        && let Some(name) = album_name
+        && !imported.is_empty()
+    {
+        let r = s.execute("album.create", &json!({"name": name}))?;
+        album = r["id"].as_u64();
+    }
+    if let Some(a) = album
+        && !imported.is_empty()
+    {
+        // (album.addPhotos wants a selection: the new photos are about to be it)
+        s.selection = Selection::single(PhotoId(imported[0]));
+        s.execute("album.addPhotos", &json!({"id": a, "ids": imported}))?;
+        report["album"] = json!(a);
+    }
+    Ok(report)
+}
+
 fn album_param(p: &Value, key: &str, c: &str) -> Result<AlbumId> {
     p.get(key).and_then(Value::as_u64).map(AlbumId).ok_or_else(|| bad(c, format!("missing album `{key}`")))
 }
@@ -164,7 +263,7 @@ pub fn specs() -> Vec<CommandSpec> {
             "Filter",
             [],
             None,
-            "partial Filter: {text?, rating?, ratingOp?: atLeast|exactly|atMost, flag?: pick|reject|none|null, label?, kind?, merged?: hdr|panorama|hdrPanorama|any, edited?, date?, keyword?, camera?}",
+            "partial Filter: {text?, rating?, ratingOp?: atLeast|exactly|atMost, flag?: pick|reject|none|null, label?, kind?, merged?: hdr|panorama|hdrPanorama|any, edited?, date?, keyword?, person?, camera?}",
             always,
             |s, p| {
                 let mut v = serde_json::to_value(&s.filter).unwrap_or_default();
@@ -347,6 +446,66 @@ pub fn specs() -> Vec<CommandSpec> {
         cmd!("photo.rotateRight", "Rotate Right", ["Photo"], Some("Cmd+]"), "{ids?}", has_selection, |s, p| rotate(s, p, true)),
         cmd!("photo.flipHorizontal", "Flip Horizontal", ["Photo"], None, "{ids?}", has_selection, |s, p| flip(s, p, true)),
         cmd!("photo.flipVertical", "Flip Vertical", ["Photo"], None, "{ids?}", has_selection, |s, p| flip(s, p, false)),
+        // ---- face / pet regions
+        cmd!(
+            "photo.removeRegion",
+            "Remove Face Box",
+            [],
+            None,
+            "{id?, index} — remove one face / pet region (by its position in the photo's regions) from the photo in the catalog; undoable. The XMP sidecar is never rewritten for this, even with auto-write on, so reading the metadata from the file brings the region back",
+            always,
+            |s, p| {
+                let id =
+                    p.get("id").and_then(Value::as_u64).map(PhotoId).or_else(|| s.active()).ok_or_else(|| bad("photo.removeRegion", "no photo"))?;
+                let index = p
+                    .get("index")
+                    .and_then(Value::as_u64)
+                    .and_then(|i| usize::try_from(i).ok())
+                    .ok_or_else(|| bad("photo.removeRegion", "missing or invalid `index`"))?;
+                let mut meta = s.catalog.photo(id).ok_or_else(|| bad("photo.removeRegion", "no such photo"))?.meta.clone();
+                if index >= meta.regions.len() {
+                    return Err(bad("photo.removeRegion", "no such region"));
+                }
+                let gone = meta.regions.remove(index);
+                s.commit("Remove Face Box", Op::SetMeta { id, meta: Box::new(meta) })?;
+                s.skip_auto_write = true;
+                Ok(json!({"removed": gone.name}))
+            }
+        ),
+        cmd!(
+            "photo.setRegion",
+            "Resize Face Box",
+            [],
+            None,
+            "{id?, index, rect: {x0, y0, x1, y1}} — set one face / pet region's box (normalized, in the photo's upright frame; clamped to the photo, at least 0.5 % each way) in the catalog; undoable. Like photo.removeRegion it never rewrites the XMP sidecar",
+            always,
+            |s, p| {
+                const C: &str = "photo.setRegion";
+                // a drag is one undo step however many frames it took: the caller commits once, on release
+                let id = p.get("id").and_then(Value::as_u64).map(PhotoId).or_else(|| s.active()).ok_or_else(|| bad(C, "no photo"))?;
+                let index = p
+                    .get("index")
+                    .and_then(Value::as_u64)
+                    .and_then(|i| usize::try_from(i).ok())
+                    .ok_or_else(|| bad(C, "missing or invalid `index`"))?;
+                let r = p.get("rect").ok_or_else(|| bad(C, "missing `rect`"))?;
+                let num = |k: &str| {
+                    r.get(k).and_then(Value::as_f64).filter(|v| v.is_finite()).ok_or_else(|| bad(C, format!("`rect.{k}` must be a finite number")))
+                };
+                let (a, b, c, d) = (num("x0")?, num("y0")?, num("x1")?, num("y1")?);
+                let (x0, x1) = (a.min(c).clamp(0.0, 1.0), a.max(c).clamp(0.0, 1.0));
+                let (y0, y1) = (b.min(d).clamp(0.0, 1.0), b.max(d).clamp(0.0, 1.0));
+                if x1 - x0 < 0.005 || y1 - y0 < 0.005 {
+                    return Err(bad(C, "the box would be too small"));
+                }
+                let mut meta = s.catalog.photo(id).ok_or_else(|| bad(C, "no such photo"))?.meta.clone();
+                let region = meta.regions.get_mut(index).ok_or_else(|| bad(C, "no such region"))?;
+                region.rect = lightcraft_geom::Rect { x0, y0, x1, y1 };
+                s.commit("Resize Face Box", Op::SetMeta { id, meta: Box::new(meta) })?;
+                s.skip_auto_write = true;
+                Ok(json!({"rect": {"x0": x0, "y0": y0, "x1": x1, "y1": y1}}))
+            }
+        ),
         // ---- delete / restore
         cmd!("photo.delete", "Delete Photo", ["Photo"], Some("Delete"), "{ids?} — moves to Recently Deleted", has_selection, |s, p| {
             let v = for_targets(s, p, "Delete", |id| Some(Op::SetDeleted { id, deleted: true }))?;
@@ -354,11 +513,11 @@ pub fn specs() -> Vec<CommandSpec> {
             s.selection = vis.first().map(|f| Selection::single(*f)).unwrap_or_default();
             Ok(v)
         }),
-        cmd!("photo.restore", "Restore", [], None, "{ids?}", has_selection, |s, p| for_targets(s, p, "Restore", |id| Some(Op::SetDeleted {
+        cmd!("photo.restore", "Restore", ["Photo"], None, "{ids?}", has_selection, |s, p| for_targets(s, p, "Restore", |id| Some(Op::SetDeleted {
             id,
             deleted: false
         }))),
-        cmd!("photo.deletePermanently", "Delete Permanently", [], None, "{ids?}", has_selection, |s, p| {
+        cmd!("photo.deletePermanently", "Delete Permanently", ["Photo"], None, "{ids?}", has_selection, |s, p| {
             let t = s.targets(p);
             let ops = t.iter().map(|id| s.catalog.delete_permanently_ops(*id)).collect::<Vec<_>>();
             s.commit("Delete Permanently", Op::Batch { ops })?;
@@ -657,9 +816,9 @@ pub fn specs() -> Vec<CommandSpec> {
             "Auto Import Now",
             [],
             None,
-            "{} — add the watched folder's new photos (files the library doesn't have yet; partial / still-copying files wait for the next scan) → {imported, folder}",
+            "{listing?: [[path, size]] (the folder as listed by the caller, e.g. on a worker thread), start?: bool (false: return the `library.import` params as `import` instead of importing)} — add the watched folder's new photos (files the library doesn't have yet; partial / still-copying files wait for the next scan) → {imported, folder, import?}",
             always,
-            |s, _| {
+            |s, p| {
                 let Some(folder) = s.import_defaults.auto_folder.clone() else { return Ok(json!({"imported": [], "folder": null})) };
                 // only files that stopped growing: a file still being written is left for later
                 let known: std::collections::HashSet<String> = s
@@ -670,18 +829,20 @@ pub fn specs() -> Vec<CommandSpec> {
                         _ => None,
                     })
                     .collect();
+                // the folder's files and sizes: listed here, or already listed on a worker thread (the app)
+                let listing: Vec<(String, u64)> = match p.get("listing").and_then(Value::as_array) {
+                    Some(l) => l.iter().filter_map(|e| Some((e.get(0)?.as_str()?.to_string(), e.get(1)?.as_u64()?))).collect(),
+                    None => list_auto_import_folder(&folder).map_err(|e| bad("library.autoImportScan", e))?,
+                };
                 let mut fresh = Vec::new();
-                for e in std::fs::read_dir(&folder).map_err(|e| bad("library.autoImportScan", format!("{folder}: {e}")))?.flatten() {
-                    let path = e.path();
-                    let ps = path.to_string_lossy().to_string();
-                    if !path.is_file() || known.contains(&ps) || path.file_name().is_some_and(|n| n.to_string_lossy().starts_with('.')) {
+                for (ps, size) in listing {
+                    if known.contains(&ps) {
                         continue;
                     }
                     // each file is tried once (a non-photo isn't retried every scan)
                     if s.auto_import_seen.get(&ps) == Some(&u64::MAX) {
                         continue;
                     }
-                    let size = e.metadata().map(|m| m.len()).unwrap_or(0);
                     let seen = s.auto_import_seen.insert(ps.clone(), size);
                     if size > 0 && seen == Some(size) {
                         fresh.push(ps);
@@ -701,6 +862,10 @@ pub fn specs() -> Vec<CommandSpec> {
                 for f in &fresh {
                     s.auto_import_seen.insert(f.clone(), u64::MAX);
                 }
+                if p.get("start").and_then(Value::as_bool) == Some(false) {
+                    // the caller imports them (the app: on a worker thread)
+                    return Ok(json!({"imported": [], "folder": folder, "import": params}));
+                }
                 let sel = s.selection.clone();
                 let r = s.execute("library.import", &params)?;
                 // arriving photos don't take over the selection
@@ -751,79 +916,15 @@ pub fn specs() -> Vec<CommandSpec> {
             "{paths: [file or folder (recursive)], mode?: add|copy|move (add = reference the files in place; copy = into the library's Originals/YYYY/YYYY-MM-DD/; move = as copy, then each original and its XMP sidecars are removed from the source — only after the copy is verified (a hard link on the same volume, else copied, synced and compared byte for byte) and its catalog record is saved; failed, duplicate and unchecked files keep their sources; a taken name gets -1, -2…; undo removes the photos from the library but leaves the files at the destination), destination?: folder for copies / moves, organize?: date (YYYY/YYYY-MM-DD) | month (YYYY/YYYY-MM) | flat | a folder template, e.g. `{date:%Y}/{date:%Y%m%d}` → 2026/20260114 (the template's `/` make the folders, each level expanded with the rename tokens and made a safe folder name: never outside the destination; must be relative, no `..`; a level with missing metadata is `unknown`) — dated by capture time, else the import time, rename?: file-name template for copies, original extension added (tokens: {name} {num} {seq} {seq:N} {date} {date:%Y%m%d} {folder} {camera} {lens} {iso} {rating} {title} {creator} {ext}; photo.renameTokens explains each; blank = keep names), renameStart?: 1, metadataPreset?: name, dng?: bool (copy raws as DNG; copy only), local?: bool (browsing: the photos stay out of the library, like library.browse; not with move), album?: albumId, albumName?: new album, preset?: presetId, keywords?: [..]} → {imported, duplicates, failed, moved?: [{from, to, sidecars?}], kept?: [{path, reason}] (move: sources left in place and why), album?}",
             always,
             |s, p| {
-                let paths = strs(p, "paths");
-                if paths.is_empty() {
+                let req = import_params(s, p)?;
+                if req.paths.is_empty() {
                     return Err(bad("library.import", "no paths"));
                 }
-                let mode = match str_param(p, "mode").unwrap_or("add") {
-                    "add" => crate::import::ImportMode::Add,
-                    "copy" => crate::import::ImportMode::Copy,
-                    "move" => crate::import::ImportMode::Move,
-                    other => return Err(bad("library.import", format!("unknown mode `{other}` (add|copy|move)"))),
-                };
-                let preset = match str_param(p, "preset").filter(|x| !x.is_empty()) {
-                    Some(id) => {
-                        Some(s.presets.iter().find(|x| x.id == id).cloned().ok_or_else(|| bad("library.import", format!("unknown preset `{id}`")))?)
-                    }
-                    None => None,
-                };
-                let mut album = p.get("album").and_then(Value::as_u64);
-                if let Some(a) = album
-                    && s.catalog.album(AlbumId(a)).is_none_or(|al| al.folder || al.is_smart())
-                {
-                    return Err(bad("library.import", "album must be a regular album"));
-                }
-                let organize = match str_param(p, "organize") {
-                    Some(o) => crate::import::Organize::parse(o).ok_or_else(|| {
-                        bad(
-                            "library.import",
-                            format!("unknown organize `{o}` (date|month|flat, or a folder template like {{date:%Y}}/{{date:%Y%m%d}})"),
-                        )
-                    })?,
-                    None => Default::default(),
-                };
-                if let crate::import::Organize::Template(t) = &organize
-                    && let Some(e) = crate::rename::folder_template_error(t)
-                {
-                    return Err(bad("library.import", e));
-                }
-                let metadata_preset = str_param(p, "metadataPreset").map(str::trim).filter(|n| !n.is_empty()).map(str::to_string);
-                if let Some(n) = &metadata_preset
-                    && !s.metadata_presets.iter().any(|m| m.name.eq_ignore_ascii_case(n))
-                {
-                    return Err(bad("library.import", format!("unknown metadata preset `{n}`")));
-                }
-                let opts = crate::import::ImportOptions {
-                    mode,
-                    preset,
-                    keywords: strs(p, "keywords"),
-                    destination: str_param(p, "destination").map(str::to_string),
-                    organize,
-                    rename: str_param(p, "rename").map(str::to_string),
-                    rename_start: p.get("renameStart").and_then(Value::as_u64).unwrap_or(1) as usize,
-                    metadata_preset,
-                    convert_dng: super::bool_or(p, "dng", false),
-                    local: super::bool_or(p, "local", false),
-                };
                 let undo0 = s.undo.len();
-                let mut report = serde_json::to_value(crate::import::import_with(s, &paths, &opts)?).unwrap_or_default();
-                let imported: Vec<u64> = report["imported"].as_array().map(|a| a.iter().filter_map(Value::as_u64).collect()).unwrap_or_default();
-                if album.is_none()
-                    && let Some(name) = str_param(p, "albumName").map(str::trim).filter(|n| !n.is_empty())
-                    && !imported.is_empty()
-                {
-                    let r = s.execute("album.create", &json!({"name": name}))?;
-                    album = r["id"].as_u64();
-                }
-                if let Some(a) = album
-                    && !imported.is_empty()
-                {
-                    // (album.addPhotos wants a selection: the new photos are about to be it)
-                    s.selection = Selection::single(PhotoId(imported[0]));
-                    s.execute("album.addPhotos", &json!({"id": a, "ids": imported}))?;
-                    report["album"] = json!(a);
-                }
+                let report = crate::import::import_with(s, &req.paths, &req.opts)?;
+                let report = import_batch_done(s, report, req.album, req.album_name.as_deref())?;
                 // one undo step for the whole import
+                let imported: Vec<u64> = report["imported"].as_array().map(|a| a.iter().filter_map(Value::as_u64).collect()).unwrap_or_default();
                 let n = s.undo.len().saturating_sub(undo0);
                 s.merge_undo(n, &format!("Add {} Photo{}", imported.len(), if imported.len() == 1 { "" } else { "s" }));
                 if let Some(f) = imported.first() {

crates/engine/src/cmd/masks.rs

@@ -5,6 +5,7 @@ use lightcraft_geom::Point;
 use serde_json::{Value, json};
 
 use super::{CommandSpec, bad, bool_or, cmd, f64_or, has_active, ok, point, str_param};
+use crate::segment::{Click, MAX_CLICKS};
 use crate::{Result, Session};
 
 fn shape_from(kind: &str, p: &Value, c: &str) -> Result<MaskShape> {
@@ -38,10 +39,100 @@ fn shape_from(kind: &str, p: &Value, c: &str) -> Result<MaskShape> {
                 .unwrap_or_default();
             MaskShape::ColorRange { samples, refine: f64_or(p, "refine", 50.0) }
         }
-        other => return Err(bad(c, format!("unknown mask kind `{other}` (brush|linear|radial|sky|subject|background|luminanceRange|colorRange)"))),
+        "object" => MaskShape::Object { hint: points(p, "points"), exclude: points(p, "exclude"), seg: seg_param(p), detail: vec![], edge: 0.0 },
+        "prompt" => {
+            MaskShape::Prompt { text: str_param(p, "text").unwrap_or_default().trim().to_string(), seg: seg_param(p), detail: vec![], edge: 0.0 }
+        }
+        other => {
+            return Err(bad(
+                c,
+                format!("unknown mask kind `{other}` (brush|linear|radial|sky|subject|background|luminanceRange|colorRange|object|prompt)"),
+            ));
+        }
     })
 }
 
+/// `[[x, y], …]` normalized points under `key`.
+fn points(p: &Value, key: &str) -> Vec<Point> {
+    p.get(key)
+        .and_then(Value::as_array)
+        .map(|a| a.iter().filter_map(|q| Some(Point::new(q.get(0)?.as_f64()?, q.get(1)?.as_f64()?))).collect())
+        .unwrap_or_default()
+}
+
+/// A segmentation passed in (`seg`: a stored or replayed AI mask; the model isn't needed).
+fn seg_param(p: &Value) -> Option<lightcraft_develop::SegMask> {
+    p.get("seg").and_then(|v| serde_json::from_value(v.clone()).ok())
+}
+
+/// What a new AI shape still needs once it is added.
+enum Later {
+    Nothing,
+    /// Background mode: these Object clicks are segmented on the worker.
+    Clicks(Vec<Point>, Vec<Point>),
+    /// Background mode: the Describe selection is computed first; the mask is added when found.
+    Text(String),
+}
+
+/// Compute the segmentation of a new AI shape (Object with clicks, Prompt) — or, in background
+/// mode, say what to queue. An Object without clicks stays empty until the photo is clicked
+/// (the photo is analyzed meanwhile); a Prompt that matches nothing is an error. Shapes given
+/// with their `seg` need no model.
+fn resolve_ai(s: &mut Session, shape: &mut MaskShape, c: &str) -> Result<Later> {
+    let id = s.active().ok_or_else(|| bad(c, "no active photo"))?;
+    let background = s.segmenter.background;
+    match shape {
+        MaskShape::Object { seg: Some(_), .. } | MaskShape::Prompt { seg: Some(_), .. } => {}
+        MaskShape::Object { hint, exclude, .. } if !hint.is_empty() && background => {
+            s.segmenter.model_dir().map_err(ai_err)?;
+            return Ok(Later::Clicks(std::mem::take(hint), std::mem::take(exclude)));
+        }
+        MaskShape::Object { hint, exclude, seg, .. } if !hint.is_empty() => {
+            *seg = Some(s.segment_clicks(id, &clicks_of(hint, exclude)).map_err(ai_err)?);
+        }
+        MaskShape::Object { .. } => {
+            // the clicks come later: refuse an Object mask that could never be computed (no
+            // model) rather than leave an empty one; in the app, analyze the photo meanwhile
+            s.segmenter.model_dir().map_err(ai_err)?;
+            if background {
+                s.segment_prepare(id).map_err(ai_err)?;
+            }
+        }
+        MaskShape::Prompt { text, .. } if background => {
+            s.segmenter.model_dir().map_err(ai_err)?;
+            if text.trim().is_empty() {
+                return Err(ai_err("describe what to select"));
+            }
+            return Ok(Later::Text(text.clone()));
+        }
+        MaskShape::Prompt { text, seg, .. } => {
+            let found = s.segment_text(id, text).map_err(ai_err)?;
+            *seg = Some(found.ok_or_else(|| ai_err(format!("nothing matching “{text}” was found in this photo")))?);
+        }
+        _ => {}
+    }
+    Ok(Later::Nothing)
+}
+
+/// Queue what a new AI component (component `comp` of mask `mask`) still needs.
+fn queue_later(s: &mut Session, later: Later, mask: u32, comp: usize, mut out: Value) -> Result<Value> {
+    if let Later::Clicks(hint, exclude) = later {
+        let id = s.active().ok_or_else(|| ai_err("no active photo"))?;
+        s.segment_clicks_later(id, mask, comp, hint, exclude).map_err(ai_err)?;
+        out["pending"] = json!(true);
+    }
+    Ok(out)
+}
+
+/// AI mask failures are shown as they are (not as "invalid parameters").
+fn ai_err(msg: impl Into<String>) -> crate::EngineError {
+    crate::EngineError::Other(msg.into())
+}
+
+pub(crate) fn clicks_of(include: &[Point], exclude: &[Point]) -> Vec<Click> {
+    include.iter().map(|p| Click { at: *p, include: true }).chain(exclude.iter().map(|p| Click { at: *p, include: false })).collect()
+}
+
 fn masks_edit(s: &mut Session, c: &str, label: &str, f: impl FnOnce(&mut Vec<Mask>, &mut Option<u32>) -> Result<()>) -> Result<Value> {
     let id = s.active().ok_or_else(|| bad(c, "no active photo"))?;
     let mut d = (*s.develop_of(id).unwrap_or_default()).clone();
@@ -67,14 +158,20 @@ pub fn specs() -> Vec<CommandSpec> {
             "Create New Mask",
             [],
             None,
-            "{kind: brush|linear|radial|sky|subject|background|luminanceRange|colorRange, ...shape params (start/end, center/rx/ry/angle/feather, lo/hi…), name?}",
+            "{kind: brush|linear|radial|sky|subject|background|luminanceRange|colorRange|object|prompt, ...shape params (start/end, center/rx/ry/angle/feather, lo/hi…; object: points/exclude [[x,y],…]; prompt: text; object/prompt: seg? a stored segmentation, no model needed), name?} — AI kinds need the SAM 3 model; in the app a prompt returns {pending} and the mask appears when found",
             has_active,
             |s, p| {
                 let kind = str_param(p, "kind").unwrap_or("radial").to_string();
-                let shape = shape_from(&kind, p, "mask.add")?;
+                let mut shape = shape_from(&kind, p, "mask.add")?;
+                let later = resolve_ai(s, &mut shape, "mask.add")?;
                 let name = str_param(p, "name").map(str::to_string);
+                if let Later::Text(text) = &later {
+                    let id = s.active().ok_or_else(|| bad("mask.add", "no active photo"))?;
+                    s.segment_text_later(id, None, "add", name, text).map_err(ai_err)?;
+                    return Ok(json!({"pending": true}));
+                }
                 let next = s.active().and_then(|id| s.develop_of(id)).map(|d| d.next_mask_id()).unwrap_or(1);
-                masks_edit(s, "mask.add", "Add Mask", |masks, active| {
+                let out = masks_edit(s, "mask.add", "Add Mask", |masks, active| {
                     masks.push(Mask {
                         id: next,
                         name: name.unwrap_or_else(|| format!("Mask {next}")),
@@ -83,7 +180,8 @@ pub fn specs() -> Vec<CommandSpec> {
                     });
                     *active = Some(next);
                     Ok(())
-                })
+                })?;
+                queue_later(s, later, next, 0, out)
             }
         ),
         cmd!(
@@ -95,16 +193,29 @@ pub fn specs() -> Vec<CommandSpec> {
             has_active,
             |s, p| {
                 let kind = str_param(p, "kind").unwrap_or("brush").to_string();
-                let shape = shape_from(&kind, p, "mask.addComponent")?;
                 let op: MaskOp =
                     serde_json::from_value(p.get("op").cloned().unwrap_or(json!("add"))).map_err(|e| bad("mask.addComponent", e.to_string()))?;
                 let active = s.active_mask;
                 let mid = mask_id(p, active, "mask.addComponent")?;
-                masks_edit(s, "mask.addComponent", "Edit Mask", |masks, _| {
+                let id = s.active().ok_or_else(|| bad("mask.addComponent", "no active photo"))?;
+                if !s.develop_of(id).is_some_and(|d| d.masks.iter().any(|m| m.id == mid)) {
+                    return Err(bad("mask.addComponent", format!("no mask {mid}")));
+                }
+                let mut shape = shape_from(&kind, p, "mask.addComponent")?;
+                let later = resolve_ai(s, &mut shape, "mask.addComponent")?;
+                if let Later::Text(text) = &later {
+                    let op = p.get("op").and_then(Value::as_str).unwrap_or("add");
+                    s.segment_text_later(id, Some(mid), op, None, text).map_err(ai_err)?;
+                    return Ok(json!({"pending": true}));
+                }
+                let mut comp = 0;
+                let out = masks_edit(s, "mask.addComponent", "Edit Mask", |masks, _| {
                     let i = find(masks, mid, "mask.addComponent")?;
                     masks[i].components.push(MaskComponent { name: None, op, invert: bool_or(p, "invert", false), shape });
+                    comp = masks[i].components.len() - 1;
                     Ok(())
-                })
+                })?;
+                queue_later(s, later, mid, comp, out)
             }
         ),
         cmd!(
@@ -185,7 +296,7 @@ pub fn specs() -> Vec<CommandSpec> {
                 let add = p.get("add").and_then(Value::as_bool).unwrap_or(false);
                 let id = s.active().ok_or_else(|| bad(c, "no active photo"))?;
                 let src = s.source_now(id, crate::media::SourceLevel::Thumb).map_err(|e| bad(c, e))?;
-                let info = s.catalog.photo(id).map(|p| crate::media::source_info(p)).unwrap_or_default();
+                let info = s.source_info(id);
                 let d = s.develop_of(id).unwrap_or_default();
                 let req = lightcraft_pipeline::RenderRequest::fit(384, 384);
                 let lab = lightcraft_pipeline::color_range_sample(&src, &info, &d, &req, lightcraft_geom::Point::new(x, y))
@@ -213,6 +324,158 @@ pub fn specs() -> Vec<CommandSpec> {
                 Ok(json!({"samples": out}))
             }
         ),
+        cmd!(
+            "mask.objectPoint",
+            "Add Object Click",
+            [],
+            None,
+            "{x, y: normalized image point, exclude?: bool (⌥-click: leave this part out), id?: maskId} — a click on the selected mask's Object selection (its last Object component); SAM 3 re-segments the object → {include, exclude}",
+            has_active,
+            |s, p| {
+                let c = "mask.objectPoint";
+                let at = Point::new(super::f64_req(p, "x", c)?, super::f64_req(p, "y", c)?);
+                if !(0.0..=1.0).contains(&at.x) || !(0.0..=1.0).contains(&at.y) {
+                    return Err(bad(c, "the point is outside the photo"));
+                }
+                let exclude = bool_or(p, "exclude", false);
+                let id = s.active().ok_or_else(|| bad(c, "no active photo"))?;
+                let mid = mask_id(p, s.active_mask, c)?;
+                let d = s.develop_of(id).unwrap_or_default();
+                let m = d.masks.iter().find(|m| m.id == mid).ok_or_else(|| bad(c, format!("no mask {mid}")))?;
+                let k = m
+                    .components
+                    .iter()
+                    .rposition(|x| matches!(x.shape, MaskShape::Object { .. }))
+                    .ok_or_else(|| bad(c, "the mask has no Object selection (add one first)"))?;
+                let Some(MaskShape::Object { hint, exclude: ex, edge, .. }) = m.components.get(k).map(|x| &x.shape) else {
+                    return Err(bad(c, "not an Object component"));
+                };
+                let (mut hint, mut ex, edge) = (hint.clone(), ex.clone(), *edge);
+                // clicks still on their way to the model count too
+                if let Some(pending) = s.segmenter.pending_clicks().filter(|q| (q.photo, q.mask, q.comp) == (id, mid, k)) {
+                    (hint, ex) = (pending.hint.clone(), pending.exclude.clone());
+                }
+                if hint.len() + ex.len() >= MAX_CLICKS {
+                    return Err(ai_err(format!("an Object selection takes at most {MAX_CLICKS} clicks; start a new one")));
+                }
+                if exclude {
+                    ex.push(at)
+                } else {
+                    hint.push(at)
+                }
+                if s.segmenter.background && !hint.is_empty() {
+                    let out = json!({"include": hint.len(), "exclude": ex.len(), "pending": true});
+                    s.segment_clicks_later(id, mid, k, hint, ex).map_err(ai_err)?;
+                    return Ok(out);
+                }
+                let seg = if hint.is_empty() { None } else { Some(s.segment_clicks(id, &clicks_of(&hint, &ex)).map_err(ai_err)?) };
+                let out = json!({"include": hint.len(), "exclude": ex.len()});
+                masks_edit(s, c, "Object Mask", |masks, _| {
+                    let i = find(masks, mid, c)?;
+                    if let Some(comp) = masks[i].components.get_mut(k) {
+                        comp.shape = MaskShape::Object { hint, exclude: ex, seg, detail: vec![], edge };
+                    }
+                    Ok(())
+                })?;
+                Ok(out)
+            }
+        ),
+        cmd!(
+            "mask.refineDetail",
+            "Refine AI Mask Detail",
+            [],
+            None,
+            "{id?: maskId, component?} — a zoomed-in SAM 3 pass over an Object/Describe selection (default: the mask's last one): the photo around it is analyzed again at a higher resolution, in the background; the mask updates when it's done → {started}",
+            has_active,
+            |s, p| {
+                let c = "mask.refineDetail";
+                let id = s.active().ok_or_else(|| bad(c, "no active photo"))?;
+                let mid = mask_id(p, s.active_mask, c)?;
+                let d = s.develop_of(id).unwrap_or_default();
+                let m = d.masks.iter().find(|m| m.id == mid).ok_or_else(|| bad(c, format!("no mask {mid}")))?;
+                let k = match p.get("component").and_then(Value::as_u64) {
+                    Some(k) => k as usize,
+                    None => m
+                        .components
+                        .iter()
+                        .rposition(|x| matches!(x.shape, MaskShape::Object { .. } | MaskShape::Prompt { .. }))
+                        .ok_or_else(|| bad(c, "the mask has no Object or Describe selection"))?,
+                };
+                let started = s.segment_detail(id, mid, k).map_err(ai_err)?;
+                Ok(json!({"started": started}))
+            }
+        ),
+        cmd!(
+            query "segment.prepare",
+            "Prepare AI Masks",
+            [],
+            None,
+            "{} — load SAM 3 and analyze the active photo in the background, so Object clicks are instant → {busy}",
+            has_active,
+            |s, _| {
+                let c = "segment.prepare";
+                let id = s.active().ok_or_else(|| bad(c, "no active photo"))?;
+                s.segment_prepare(id).map_err(ai_err)?;
+                Ok(json!({"busy": s.segmenter.busy()}))
+            }
+        ),
+        cmd!(
+            query "segment.model.status",
+            "AI Mask Model Status",
+            [],
+            None,
+            "{} — whether this build has AI masks, whether the SAM 3 model is installed (and where), loaded, busy, and the download's progress → {available, installed, dir, loaded, busy, analyzing, sizeBytes, license, licenseUrl, mirrors, download: {running, done, total, file, error, finished}}",
+            super::always,
+            |s, _| {
+                let g = &s.segmenter;
+                Ok(json!({
+                    "available": crate::segment::Segmenter::AVAILABLE,
+                    "installed": g.installed(),
+                    "dir": g.dir.as_ref().map(|d| d.display().to_string()),
+                    "loaded": g.loaded(),
+                    "busy": g.busy(),
+                    "analyzing": g.analyzing(),
+                    "sizeBytes": crate::segment::MODEL_BYTES,
+                    "license": crate::segment::LICENSE_NAME,
+                    "licenseUrl": crate::segment::LICENSE_URL,
+                    "mirrors": g.mirrors().len(),
+                    "download": g.download_status(),
+                }))
+            }
+        ),
+        cmd!(
+            query "segment.model.download",
+            "Download AI Mask Model",
+            [],
+            None,
+            "{acknowledged: true} — download the SAM 3 model (about 3.4 GB, Meta's SAM License, not LightCraft's) in the background, from the configured mirrors; only after the user agreed to it. Watch segment.model.status; segment.model.cancel stops it (it resumes later) → {started, installed, downloading}",
+            super::always,
+            |s, p| {
+                let c = "segment.model.download";
+                if p.get("acknowledged").and_then(Value::as_bool) != Some(true) {
+                    return Err(bad(
+                        c,
+                        format!(
+                            "the SAM 3 model is a {:.1} GB download under Meta's {} ({}): pass `acknowledged: true` once the user has agreed to download it",
+                            crate::segment::MODEL_BYTES as f64 / 1e9,
+                            crate::segment::LICENSE_NAME,
+                            crate::segment::LICENSE_URL
+                        ),
+                    ));
+                }
+                let started = s.segmenter.start_download().map_err(ai_err)?;
+                Ok(json!({"started": started, "installed": s.segmenter.installed(), "downloading": s.segmenter.download_status().running}))
+            }
+        ),
+        cmd!(
+            query "segment.model.cancel",
+            "Cancel AI Mask Model Download",
+            [],
+            None,
+            "{} — stop the SAM 3 download (what has arrived is kept, and a new download resumes from it) → {cancelled}",
+            super::always,
+            |s, _| Ok(json!({"cancelled": s.segmenter.cancel_download()}))
+        ),
         cmd!(
             "mask.refine",
             "Refine Mask Edges",
@@ -646,7 +909,7 @@ fn spots_edit(s: &mut Session, c: &str, label: &str, f: impl FnOnce(&mut Vec<Spo
 /// An automatic source for `spot` on photo `id` (a small proxy of the photo, framed by `d`).
 fn pick_source(s: &mut Session, id: crate::PhotoId, d: &lightcraft_develop::DevelopSettings, spot: &Spot, avoid: Option<Point>) -> Option<Point> {
     let src = s.source_now(id, crate::media::SourceLevel::Thumb).ok()?;
-    let info = crate::media::source_info(s.catalog.photo(id)?);
+    let info = s.source_info(id);
     lightcraft_pipeline::spots::pick_source(&src, &info, d, spot, avoid)
 }
 

crates/engine/src/cmd/missing.rs

@@ -45,9 +45,10 @@ pub fn missing(s: &Session) -> Vec<(PhotoId, String)> {
 }
 
 /// Whether photo `id` is in scope and its file is gone (the Missing Photos view checks only
-/// the photos its query already narrowed to).
-pub fn is_missing(cat: &Catalog, id: PhotoId) -> bool {
-    !cfg!(target_arch = "wasm32") && cat.photo(id).and_then(|p| checked_path(p)).is_some_and(|f| !Path::new(f).exists())
+/// the photos its query already narrowed to). In the app `avail` answers from its cache (files
+/// not checked yet count as present until the background check finds them gone).
+pub fn is_missing(cat: &Catalog, avail: &crate::availability::Availability, id: PhotoId) -> bool {
+    !cfg!(target_arch = "wasm32") && cat.photo(id).and_then(|p| checked_path(p)).is_some_and(|f| avail.is_offline(f))
 }
 
 fn relink_op(id: PhotoId, path: &str) -> Op {
@@ -94,8 +95,112 @@ fn file_hash(path: &str) -> Option<String> {
     std::fs::read(path).ok().map(|b| lightcraft_preview::hash_bytes(&b).to_string())
 }
 
-/// Search `folder` (recursively) for each missing photo's file and relink every match in one
-/// undoable step.
+/// An in-scope photo ([`checked_path`]) as Find Missing Photos sees it: its file, the size and
+/// content hash the library knows (0 / `None` = unknown).
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub struct FindCandidate {
+    pub id: PhotoId,
+    pub path: String,
+    pub size: u64,
+    pub hash: Option<String>,
+}
+
+/// Every in-scope photo, for [`plan_find_missing`]: the missing ones are looked for, and no
+/// photo's file is used for another. No file-system calls, so the app takes this snapshot on the
+/// UI thread and plans on a worker without holding the session.
+pub fn find_candidates(cat: &Catalog) -> Vec<FindCandidate> {
+    cat.photos()
+        .filter_map(|p| {
+            checked_path(p).map(|f| FindCandidate { id: p.id, path: f.to_string(), size: p.file_size, hash: stored_hash(p).map(str::to_string) })
+        })
+        .collect()
+}
+
+/// How a missing photo's file was recognised.
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub enum MatchBy {
+    /// Same name and size (and content, when the library knows its hash).
+    Name,
+    /// Renamed: same size and content hash.
+    Content,
+}
+
+impl MatchBy {
+    pub fn as_str(self) -> &'static str {
+        match self {
+            MatchBy::Name => "name",
+            MatchBy::Content => "content",
+        }
+    }
+}
+
+/// A missing photo and the file found for it.
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub struct FoundFile {
+    pub id: PhotoId,
+    pub from: String,
+    pub to: String,
+    pub by: MatchBy,
+}
+
+/// A missing photo with several look-alike files (same name and size, no hash to tell them
+/// apart): skipped, never guessed.
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub struct AmbiguousFile {
+    pub id: PhotoId,
+    pub from: String,
+    pub candidates: Vec<String>,
+}
+
+/// What Find Missing Photos found ([`plan_find_missing`]), before relinking.
+#[derive(Clone, Debug, Default, PartialEq, Eq)]
+pub struct FindPlan {
+    pub found: Vec<FoundFile>,
+    /// In-scope photos that stay missing (the ambiguous ones included).
+    pub missing: usize,
+    pub ambiguous: Vec<AmbiguousFile>,
+}
+
+impl FindPlan {
+    /// `{found: [{id, from, to, by}], missing, ambiguous: [{id, from, candidates}]}` — the
+    /// command's result, and what `library.findMissing {found, …}` takes back.
+    pub fn to_json(&self) -> Value {
+        let found: Vec<Value> = self.found.iter().map(|f| json!({"id": f.id.0, "from": f.from, "to": f.to, "by": f.by.as_str()})).collect();
+        let ambiguous: Vec<Value> = self.ambiguous.iter().map(|a| json!({"id": a.id.0, "from": a.from, "candidates": a.candidates})).collect();
+        json!({"found": found, "missing": self.missing, "ambiguous": ambiguous})
+    }
+
+    /// The inverse of [`FindPlan::to_json`] (entries it can't read are dropped).
+    pub fn from_json(v: &Value) -> FindPlan {
+        let list = |k: &str| v.get(k).and_then(Value::as_array).cloned().unwrap_or_default();
+        let found = list("found")
+            .iter()
+            .filter_map(|f| {
+                let by = if f.get("by").and_then(Value::as_str) == Some("content") { MatchBy::Content } else { MatchBy::Name };
+                Some(FoundFile {
+                    id: PhotoId(f.get("id")?.as_u64()?),
+                    from: str_param(f, "from")?.to_string(),
+                    to: str_param(f, "to")?.to_string(),
+                    by,
+                })
+            })
+            .collect();
+        let ambiguous = list("ambiguous")
+            .iter()
+            .filter_map(|a| {
+                let candidates = a.get("candidates")?.as_array()?.iter().filter_map(|c| c.as_str().map(str::to_string)).collect();
+                Some(AmbiguousFile { id: PhotoId(a.get("id")?.as_u64()?), from: str_param(a, "from")?.to_string(), candidates })
+            })
+            .collect();
+        let missing = v.get("missing").and_then(Value::as_u64).map_or(0, |n| usize::try_from(n).unwrap_or(usize::MAX));
+        FindPlan { found, missing, ambiguous }
+    }
+}
+
+/// The file-system half of Find Missing Photos: which `candidates` are gone, and which file in
+/// `folder` (recursively) is each one's. Touches only the disk — never the session — so the app
+/// runs it on a worker thread (walking a big folder on a network share and hashing look-alikes
+/// takes a while) and relinks the result with `library.findMissing {found, missing, ambiguous}`.
 ///
 /// Matching, per photo:
 /// 1. a file with the same name (any letter case), the same size and the same content hash;
@@ -107,20 +212,21 @@ fn file_hash(path: &str) -> Option<String> {
 ///
 /// Files that are already some photo's original, or that another photo was just matched with,
 /// are not used.
-fn find_missing(s: &mut Session, p: &Value) -> Result<Value> {
-    const C: &str = "library.findMissing";
-    let folder = str_param(p, "folder").ok_or_else(|| bad(C, "missing `folder`"))?;
+pub fn plan_find_missing(candidates: &[FindCandidate], folder: &str) -> std::result::Result<FindPlan, String> {
     if !Path::new(folder).is_dir() {
-        return Err(bad(C, format!("{folder}: not a folder")));
+        return Err(format!("{folder}: not a folder"));
     }
-    let lost = missing(s);
+    if cfg!(target_arch = "wasm32") {
+        return Ok(FindPlan::default());
+    }
+    let lost: Vec<&FindCandidate> = candidates.iter().filter(|c| !Path::new(&c.path).exists()).collect();
     if lost.is_empty() {
-        return Ok(json!({"found": [], "missing": 0, "ambiguous": []}));
+        return Ok(FindPlan::default());
     }
-    let in_use: HashSet<String> = s.catalog.photos().filter_map(|p| checked_path(p).map(str::to_string)).collect();
+    let in_use: HashSet<&str> = candidates.iter().map(|c| c.path.as_str()).collect();
     // file name (lower case) → candidate paths; size → paths (filled lazily)
     let mut by_name: HashMap<String, Vec<String>> = HashMap::new();
-    let files: Vec<String> = crate::import::expand(&[folder.to_string()], None).into_iter().filter(|f| !in_use.contains(f)).collect();
+    let files: Vec<String> = crate::import::expand(&[folder.to_string()], None).into_iter().filter(|f| !in_use.contains(f.as_str())).collect();
     for f in &files {
         if let Some(n) = Path::new(f).file_name() {
             by_name.entry(n.to_string_lossy().to_lowercase()).or_default().push(f.clone());
@@ -131,24 +237,21 @@ fn find_missing(s: &mut Session, p: &Value) -> Result<Value> {
     let mut hash_of = |f: &str| hashes.entry(f.to_string()).or_insert_with(|| file_hash(f)).clone();
     let size_of = |f: &str| std::fs::metadata(f).map(|m| m.len()).ok();
     let mut used: HashSet<String> = HashSet::new();
-    let mut ops = Vec::new();
-    let mut found = Vec::new();
-    let mut ambiguous = Vec::new();
-    for (id, old) in &lost {
-        let Some(ph) = s.catalog.photo(*id) else { continue };
-        let name = Path::new(old).file_name().map(|n| n.to_string_lossy().to_lowercase()).unwrap_or_default();
-        let size = ph.file_size;
-        let hash = stored_hash(ph).map(str::to_string);
+    let mut plan = FindPlan::default();
+    for c in &lost {
+        let name = Path::new(&c.path).file_name().map(|n| n.to_string_lossy().to_lowercase()).unwrap_or_default();
+        let size = c.size;
+        let hash = c.hash.as_deref();
         let named: Vec<&String> = by_name
             .get(&name)
-            .map(|c| c.iter().filter(|f| !used.contains(*f) && (size == 0 || size_of(f) == Some(size))).collect())
+            .map(|v| v.iter().filter(|f| !used.contains(*f) && (size == 0 || size_of(f) == Some(size))).collect())
             .unwrap_or_default();
         // 1. same name and size, confirmed by the content hash
-        let mut hit: Option<(String, &str)> =
-            hash.as_deref().and_then(|h| named.iter().find(|f| hash_of(f).as_deref() == Some(h))).map(|f| (f.to_string(), "name"));
+        let mut hit: Option<(String, MatchBy)> =
+            hash.and_then(|h| named.iter().find(|f| hash_of(f).as_deref() == Some(h))).map(|f| (f.to_string(), MatchBy::Name));
         // 2. renamed: same size and content
         if hit.is_none()
-            && let Some(h) = &hash
+            && let Some(h) = hash
             && size > 0
         {
             let sizes = by_size.get_or_insert_with(|| {
@@ -162,36 +265,75 @@ fn find_missing(s: &mut Session, p: &Value) -> Result<Value> {
             });
             hit = sizes
                 .get(&size)
-                .and_then(|c| c.iter().find(|f| !used.contains(*f) && hash_of(f).as_deref() == Some(h.as_str())))
-                .map(|f| (f.clone(), "content"));
+                .and_then(|v| v.iter().find(|f| !used.contains(*f) && hash_of(f).as_deref() == Some(h)))
+                .map(|f| (f.clone(), MatchBy::Content));
         }
         // 3. same name and size only (no hash, or the file was edited in place): one candidate
         //    is taken, several are ambiguous and skipped rather than guessed
         if hit.is_none() {
-            match named.len() {
-                1 => hit = Some((named[0].clone(), "name")),
-                0 => {}
+            match named.as_slice() {
+                [one] => hit = Some(((*one).clone(), MatchBy::Name)),
+                [] => {}
                 _ => {
-                    ambiguous.push(json!({"id": id.0, "from": old, "candidates": named}));
+                    plan.ambiguous.push(AmbiguousFile { id: c.id, from: c.path.clone(), candidates: named.iter().map(|f| (*f).clone()).collect() });
                     continue;
                 }
             }
         }
         let Some((path, by)) = hit else { continue };
-        ops.push(relink_op(*id, &path));
-        found.push(json!({"id": id.0, "from": old, "to": path, "by": by}));
-        used.insert(path);
+        used.insert(path.clone());
+        plan.found.push(FoundFile { id: c.id, from: c.path.clone(), to: path, by });
     }
-    let still = lost.len() - found.len();
-    if !ops.is_empty() {
-        s.commit("Find Missing Photos", Op::Batch { ops })?;
+    plan.missing = lost.len() - plan.found.len();
+    Ok(plan)
+}
+
+/// Relink what [`plan_find_missing`] found, in one undoable step, re-checked against the
+/// catalog as it is now (the search may have run on a worker while the library changed): a
+/// photo that no longer points at the path it was missing from (relinked, removed) is left
+/// alone, and a file that is now some photo's original — or that the plan names twice — is not
+/// used (that photo stays missing). `missing` is the plan's count, corrected for what changed
+/// among the photos the plan names.
+fn commit_find(s: &mut Session, plan: FindPlan) -> Result<Value> {
+    let still_at = |cat: &Catalog, id: PhotoId, from: &str| cat.photo(id).and_then(|p| checked_path(p)) == Some(from);
+    let mut in_use: HashSet<String> = candidates(&s.catalog).into_iter().collect();
+    let mut found = Vec::new();
+    let mut missing = plan.missing;
+    for f in plan.found {
+        if !still_at(&s.catalog, f.id, &f.from) {
+            continue;
+        }
+        if in_use.contains(&f.to) {
+            missing += 1;
+            continue;
+        }
+        in_use.insert(f.to.clone());
+        found.push(f);
+    }
+    let planned = plan.ambiguous.len();
+    let ambiguous: Vec<AmbiguousFile> = plan.ambiguous.into_iter().filter(|a| still_at(&s.catalog, a.id, &a.from)).collect();
+    // ambiguous photos relinked meanwhile aren't missing any more
+    missing = missing.saturating_sub(planned - ambiguous.len());
+    if !found.is_empty() {
+        s.commit("Find Missing Photos", Op::Batch { ops: found.iter().map(|f| relink_op(f.id, &f.to)).collect() })?;
         for f in &found {
-            if let Some(id) = f["id"].as_u64() {
-                s.media.forget(PhotoId(id));
-            }
+            s.media.forget(f.id);
         }
     }
-    Ok(json!({"found": found, "missing": still, "ambiguous": ambiguous}))
+    Ok(FindPlan { found, missing, ambiguous }.to_json())
+}
+
+/// Search `folder` (recursively) for each missing photo's file ([`plan_find_missing`]) and
+/// relink every match in one undoable step. With `found` instead (what a search on a worker
+/// thread returned, as `{found, missing, ambiguous}`), only the relinking is done.
+fn find_missing(s: &mut Session, p: &Value) -> Result<Value> {
+    const C: &str = "library.findMissing";
+    if p.get("found").is_some_and(Value::is_array) {
+        return commit_find(s, FindPlan::from_json(p));
+    }
+    let folder = str_param(p, "folder").ok_or_else(|| bad(C, "missing `folder`"))?;
+    let plan = plan_find_missing(&find_candidates(&s.catalog), folder).map_err(|e| bad(C, e))?;
+    commit_find(s, plan)
 }
 
 pub fn specs() -> Vec<CommandSpec> {
@@ -213,7 +355,7 @@ pub fn specs() -> Vec<CommandSpec> {
             "Find Missing Photos",
             [],
             None,
-            "{folder} — relink every missing photo whose file is somewhere in the folder: same name and size (and content, when the library knows its hash), or — renamed — same size and content → {found: [{id, from, to, by: name|content}], missing, ambiguous: [{id, from, candidates}] (several same-name candidates and no hash to tell them apart: skipped)}",
+            "{folder} — relink every missing photo whose file is somewhere in the folder: same name and size (and content, when the library knows its hash), or — renamed — same size and content; or {found, missing, ambiguous} — relink what a search already found (the app searches on a worker thread; photos relinked meanwhile and files now in use are skipped) → {found: [{id, from, to, by: name|content}], missing, ambiguous: [{id, from, candidates}] (several same-name candidates and no hash to tell them apart: skipped)}",
             always,
             find_missing
         ),

crates/engine/src/cmd/mod.rs

@@ -15,7 +15,7 @@ mod edit;
 mod export;
 pub mod filters;
 pub mod keywords;
-mod library;
+pub mod library;
 pub mod lut_profiles;
 pub mod manage;
 mod masks;

crates/engine/src/cmd/previews.rs

@@ -23,6 +23,12 @@ pub struct PreviewBuild {
     pub failed: AtomicUsize,
     pub cancel: AtomicBool,
     pub finished: AtomicBool,
+    /// Damaged smart previews rebuilt (Build Smart Previews only).
+    pub repaired: AtomicUsize,
+    /// What is built ("" = previews; "smart previews" — Build Smart Previews runs the same way).
+    pub what: &'static str,
+    /// Why the whole build failed (e.g. the smart previews folder isn't there).
+    pub error: std::sync::Mutex<Option<String>>,
 }
 
 impl PreviewBuild {
@@ -33,8 +39,15 @@ impl PreviewBuild {
             "failed": self.failed.load(Ordering::Relaxed),
             "running": !self.finished.load(Ordering::Relaxed),
             "cancelled": self.cancel.load(Ordering::Relaxed),
+            "what": if self.what.is_empty() { "previews" } else { self.what },
+            "repaired": self.repaired.load(Ordering::Relaxed),
+            "error": self.error(),
         })
     }
+
+    pub fn error(&self) -> Option<String> {
+        self.error.lock().unwrap_or_else(std::sync::PoisonError::into_inner).clone()
+    }
 }
 
 /// The jobs that build `id`'s previews: the largest grid thumbnail, then the view render at
@@ -94,56 +107,136 @@ fn build(s: &mut Session, p: &Value) -> Result<Value> {
     Ok(state.json())
 }
 
+/// One photo's smart preview to build or discard: (photo, its file in the smart previews folder,
+/// how to load the original at preview size).
+#[cfg(not(target_arch = "wasm32"))]
+type SmartJob = (lightcraft_catalog::PhotoId, std::path::PathBuf, Option<crate::media::SourceRef>);
+
+/// What Build / Discard Smart Previews did.
+#[cfg(not(target_arch = "wasm32"))]
+#[derive(Default)]
+struct SmartCounts {
+    /// Proxies there now (complete ones kept, missing or damaged ones written).
+    built: usize,
+    /// Of those, damaged ones (cut short by a crash or a full drive) that were rebuilt.
+    repaired: usize,
+    removed: usize,
+    /// `[[id, why]]`
+    failed: Vec<Value>,
+}
+
+/// The file-system half of Build / Discard Smart Previews (runs on a worker thread in the app).
+/// `custom`: the folder was chosen (on another drive, perhaps): it must be there, it is never
+/// recreated. With `state`, progress and cancel.
+#[cfg(not(target_arch = "wasm32"))]
+fn smart_run(
+    dir: &std::path::Path,
+    custom: bool,
+    discard: bool,
+    jobs: Vec<SmartJob>,
+    state: Option<&PreviewBuild>,
+) -> std::result::Result<SmartCounts, String> {
+    let mut n = SmartCounts::default();
+    if !discard {
+        // a chosen folder on another drive must be there: never recreate it on this one
+        if custom {
+            crate::smart::check_writable(dir)?;
+        } else {
+            std::fs::create_dir_all(dir).map_err(|e| format!("{}: {e}", dir.display()))?;
+        }
+    }
+    for (id, path, source) in jobs {
+        if state.is_some_and(|st| st.cancel.load(Ordering::Relaxed)) {
+            break;
+        }
+        if discard {
+            if std::fs::remove_file(&path).is_ok() {
+                n.removed += 1;
+            }
+        } else {
+            // a complete proxy is kept; a missing or damaged one (cut short by a crash or a full
+            // drive) is (re)built
+            let damaged = path.exists();
+            if damaged && crate::smart::is_valid(&path) {
+                n.built += 1;
+            } else {
+                // atomic: a failed write leaves no partial proxy that would pass for a built one;
+                // and synced (issue #134): built so the photo can be edited while its original
+                // is offline, when it is the only copy — the sync is small next to the decode
+                let r = source
+                    .ok_or_else(|| "nothing to build from".to_string())
+                    .and_then(|s| s.load_source())
+                    .and_then(|src| crate::smart::encode(&src.image, src.info_or(Default::default()).camera_tone.as_ref()))
+                    .and_then(|b| lightcraft_catalog::safe_file::write_atomic(&path, &b).map_err(|e| format!("{}: {e}", path.display())));
+                match r {
+                    Ok(()) => {
+                        n.built += 1;
+                        if damaged {
+                            n.repaired += 1;
+                            if let Some(st) = state {
+                                st.repaired.fetch_add(1, Ordering::Relaxed);
+                            }
+                        }
+                    }
+                    Err(e) => {
+                        n.failed.push(json!([id.0, e]));
+                        if let Some(st) = state {
+                            st.failed.fetch_add(1, Ordering::Relaxed);
+                        }
+                    }
+                }
+            }
+        }
+        if let Some(st) = state {
+            st.done.fetch_add(1, Ordering::Relaxed);
+        }
+    }
+    Ok(n)
+}
+
 /// Smart previews: build (from the original, at preview size) or discard the proxies that keep
-/// photos editable while their originals are offline.
+/// photos editable while their originals are offline. With `background` (the app) the files are
+/// read and written on a worker thread; progress like Build Previews (`library.previewProgress`).
 #[cfg(not(target_arch = "wasm32"))]
 fn smart(s: &mut Session, p: &Value) -> Result<Value> {
     const C: &str = "library.smartPreviews";
     let dir = s.media.smart_dir.clone().ok_or_else(|| bad(C, "smart previews need a library on disk"))?;
     let discard = p.get("discard").and_then(Value::as_bool).unwrap_or(false);
-    let ids = if p.get("ids").is_some() || !s.selection.ids.is_empty() { s.targets(p) } else { s.visible_cloned() };
-    let (mut built, mut repaired, mut removed, mut failed) = (0usize, 0usize, 0usize, Vec::new());
-    if !discard {
-        // a chosen folder on another drive must be there: never recreate it on this one
-        if s.smart_previews_dir.is_some() {
-            crate::smart::check_writable(&dir).map_err(|e| bad(C, e))?;
-        } else {
-            std::fs::create_dir_all(&dir).map_err(|e| bad(C, format!("{}: {e}", dir.display())))?;
-        }
+    let background = p.get("background").and_then(Value::as_bool).unwrap_or(false);
+    if background && s.preview_build.as_ref().is_some_and(|b| !b.finished.load(Ordering::Relaxed)) {
+        return Err(bad(C, "a preview build is already running"));
     }
+    let ids = if p.get("ids").is_some() || !s.selection.ids.is_empty() { s.targets(p) } else { s.visible_cloned() };
+    let mut jobs: Vec<SmartJob> = Vec::new();
     for id in ids {
         let Some(ph) = s.catalog.photo(id).cloned() else { continue };
         if !matches!(ph.source, lightcraft_catalog::Source::File { .. }) {
             continue;
         }
         let path = dir.join(crate::smart::file_name(&ph));
-        if discard {
-            if std::fs::remove_file(&path).is_ok() {
-                removed += 1;
-            }
-            continue;
-        }
-        // a complete proxy is kept; a missing or damaged one (cut short by a crash or a full
-        // drive) is (re)built
-        let damaged = path.exists();
-        if damaged && crate::smart::is_valid(&path) {
-            built += 1;
-            continue;
-        }
-        // atomic: a failed write leaves no partial proxy that would pass for a built one
-        let r = s
-            .source_now(id, crate::media::SourceLevel::Preview)
-            .and_then(|src| crate::smart::encode(&src))
-            .and_then(|b| lightcraft_catalog::safe_file::write_atomic(&path, &b).map_err(|e| format!("{}: {e}", path.display())));
-        match r {
-            Ok(()) => {
-                built += 1;
-                repaired += usize::from(damaged);
-            }
-            Err(e) => failed.push(json!([id.0, e])),
-        }
+        let source = (!discard).then(|| s.media.source_ref(&ph, crate::media::SourceLevel::Preview));
+        jobs.push((id, path, source));
     }
-    Ok(json!({"built": built, "repaired": repaired, "removed": removed, "failed": failed}))
+    let custom = s.smart_previews_dir.is_some();
+    if background {
+        let what = if discard { "discarding smart previews" } else { "smart previews" };
+        let state = Arc::new(PreviewBuild { total: jobs.len(), what, ..Default::default() });
+        s.preview_build = Some(state.clone());
+        let st = state.clone();
+        std::thread::Builder::new()
+            .name("lc-smart-previews".into())
+            .spawn(move || {
+                if let Err(e) = smart_run(&dir, custom, discard, jobs, Some(&st)) {
+                    log::warn!("{C}: {e}");
+                    *st.error.lock().unwrap_or_else(std::sync::PoisonError::into_inner) = Some(e);
+                }
+                st.finished.store(true, Ordering::Relaxed);
+            })
+            .map_err(|e| bad(C, format!("could not start: {e}")))?;
+        return Ok(state.json());
+    }
+    let r = smart_run(&dir, custom, discard, jobs, None).map_err(|e| bad(C, e))?;
+    Ok(json!({"built": r.built, "repaired": r.repaired, "removed": r.removed, "failed": r.failed}))
 }
 
 /// The smart previews folder: where it is, whether it is custom, what it holds, whether it can be
@@ -225,7 +318,7 @@ pub fn specs() -> Vec<CommandSpec> {
             "Build Smart Previews",
             [],
             None,
-            "{ids?, discard?: bool} — build (or discard) the smart previews of the selected photos (else all in view): compact proxies in the library that keep photos editable and exportable (at proxy size) while their originals are offline; a damaged proxy (cut short) is rebuilt → {built, repaired, removed, failed}",
+            "{ids?, discard?: bool, background?: bool} — build (or discard) the smart previews of the selected photos (else all in view): compact proxies in the library that keep photos editable and exportable (at proxy size) while their originals are offline; a damaged proxy (cut short) is rebuilt → {built, repaired, removed, failed}; with background (the app's menu) the files are read and written on a worker thread → {total, done, failed, repaired, running, what} like library.buildPreviews (progress: library.previewProgress, stop: library.cancelPreviews)",
             always,
             smart
         ),
@@ -256,7 +349,7 @@ pub fn specs() -> Vec<CommandSpec> {
             always,
             build
         ),
-        cmd!(query "library.previewProgress", "Preview Build Progress", [], None, "{} → {total, done, failed, running, cancelled} | null", always, |s, _| {
+        cmd!(query "library.previewProgress", "Preview Build Progress", [], None, "{} → {total, done, failed, repaired, running, cancelled, what, error} | null", always, |s, _| {
             Ok(s.preview_build.as_ref().map_or(Value::Null, |b| b.json()))
         }),
         cmd!("library.cancelPreviews", "Cancel Preview Build", [], None, "{}", always, |s, _| {

crates/engine/src/export.rs

@@ -244,14 +244,24 @@ impl Default for Watermark {
 
 /// Inter SemiBold (OFL, see assets/ATTRIBUTION.md).
 static WATERMARK_FONT: &[u8] = include_bytes!("../../../assets/fonts/Inter-SemiBold.ttf");
-/// BIZ UDMincho (OFL), Japanese fallback on both native and web.
-/// Bundled OFL Japanese font bytes, shared by watermarks and UI glyph fallback.
-pub static WATERMARK_JAPANESE_FONT: &[u8] = include_bytes!("../../../assets/fonts/BIZUDMincho-Regular.ttf");
+
+/// The watermark faces: Inter first, then the craft-fonts CJK faces (Mincho first, the watermark's
+/// serif look; then any other CJK face — a watermark has no UI language, so every CJK script is
+/// offered). Without craft-fonts that is Inter alone, and CJK characters draw as Inter's
+/// missing-glyph box.
+fn watermark_fonts(craft: &'static [crate::fonts::CraftFont]) -> Vec<ab_glyph::FontRef<'static>> {
+    let mut cjk: Vec<_> = crate::fonts::cjk(craft).collect();
+    cjk.sort_by_key(|f| !f.is_mincho());
+    std::iter::once(WATERMARK_FONT)
+        .chain(cjk.into_iter().map(|f| f.bytes))
+        .filter_map(|bytes| ab_glyph::FontRef::try_from_slice(bytes).ok())
+        .collect()
+}
 
 /// Draw `wm` onto `img` (straight alpha blending of the encoded values).
 pub fn draw_watermark(img: &mut Rgba8, wm: &Watermark) {
     let width = img.width;
-    watermark_coverage(img.width, img.height, wm, |x, y, k, col| {
+    watermark_coverage(img.width, img.height, wm, crate::fonts::CRAFT_FONTS, |x, y, k, col| {
         let p = &mut img.data[y * width + x];
         for c in 0..3 {
             p[c] = (p[c] as f32 + (col[c] as f32 - p[c] as f32) * k).round() as u8;
@@ -264,14 +274,14 @@ pub fn draw_watermark(img: &mut Rgba8, wm: &Watermark) {
 pub fn draw_watermark_deep(img: &mut DeepImage, wm: &Watermark) {
     let (width, trc) = (img.width, img.space.trc());
     match &mut img.samples {
-        DeepSamples::U16(v) => watermark_coverage(img.width, img.height, wm, |x, y, k, col| {
+        DeepSamples::U16(v) => watermark_coverage(img.width, img.height, wm, crate::fonts::CRAFT_FONTS, |x, y, k, col| {
             let i = (y * width + x) * 3;
             for c in 0..3 {
                 let p = v[i + c] as f32;
                 v[i + c] = (p + (col[c] as f32 * 257.0 - p) * k).round().clamp(0.0, 65535.0) as u16;
             }
         }),
-        DeepSamples::F32(v) => watermark_coverage(img.width, img.height, wm, |x, y, k, col| {
+        DeepSamples::F32(v) => watermark_coverage(img.width, img.height, wm, crate::fonts::CRAFT_FONTS, |x, y, k, col| {
             let i = (y * width + x) * 3;
             for c in 0..3 {
                 let target = trc.decode(col[c] as f32 / 255.0);
@@ -282,9 +292,16 @@ pub fn draw_watermark_deep(img: &mut DeepImage, wm: &Watermark) {
 }
 
 /// Lay out `wm` on a `width × height` image and call `blend(x, y, coverage × opacity, colour)` for
-/// every covered pixel (shadow pass first).
-fn watermark_coverage(width: usize, height: usize, wm: &Watermark, mut blend_px: impl FnMut(usize, usize, f32, [u8; 3])) {
-    use ab_glyph::{Font, FontRef, PxScale, ScaleFont, point};
+/// every covered pixel (shadow pass first). `craft` is [`crate::fonts::CRAFT_FONTS`] (a parameter
+/// so tests can render without it).
+fn watermark_coverage(
+    width: usize,
+    height: usize,
+    wm: &Watermark,
+    craft: &'static [crate::fonts::CraftFont],
+    mut blend_px: impl FnMut(usize, usize, f32, [u8; 3]),
+) {
+    use ab_glyph::{Font, PxScale, ScaleFont, point};
     if !wm.image.trim().is_empty() {
         logo_coverage(width, height, wm, blend_px);
         return;
@@ -293,9 +310,8 @@ fn watermark_coverage(width: usize, height: usize, wm: &Watermark, mut blend_px:
     if text.is_empty() || width == 0 || height == 0 {
         return;
     }
-    let Ok(font) = FontRef::try_from_slice(WATERMARK_FONT) else { return };
-    let Ok(japanese) = FontRef::try_from_slice(WATERMARK_JAPANESE_FONT) else { return };
-    let fonts = [font, japanese];
+    let fonts = watermark_fonts(craft);
+    let Some(latin) = fonts.first() else { return };
     let short = width.min(height) as f32;
     let px = (wm.size.clamp(0.005, 0.5) * short).max(6.0);
     let mut glyphs = Vec::new();
@@ -333,9 +349,11 @@ fn watermark_coverage(width: usize, height: usize, wm: &Watermark, mut blend_px:
             '…' => '︙',
             other => other,
         };
-        let ch = if wm.vertical && fonts[1].glyph_id(vertical_form).0 != 0 { vertical_form } else { original };
-        let face = usize::from(fonts[0].glyph_id(ch).0 == 0);
-        let sf = fonts[face].as_scaled(PxScale::from(px));
+        let has = |font: &ab_glyph::FontRef<'_>, c: char| font.glyph_id(c).0 != 0;
+        let ch = if wm.vertical && fonts.iter().skip(1).any(|f| has(f, vertical_form)) { vertical_form } else { original };
+        // The first face with the glyph; Inter (its missing-glyph box) when none has it.
+        let face = fonts.iter().position(|f| has(f, ch)).unwrap_or(0);
+        let sf = fonts.get(face).unwrap_or(latin).as_scaled(PxScale::from(px));
         let id = sf.glyph_id(ch);
         if wm.vertical {
             let left = columns.saturating_sub(column.saturating_add(1)) as f32 * px;
@@ -1131,15 +1149,27 @@ pub fn export_batch(
 }
 
 /// Write an exported or rendered file on disk: its folder is created if needed, and the file is
-/// replaced atomically ([`lightcraft_catalog::safe_file::write_atomic`]: a temp file, synced, then
-/// renamed), so a failure part-way leaves any previous file intact and no truncated one. The
-/// native writer behind exports, renders and screenshots (app, CLI, MCP).
+/// replaced atomically ([`lightcraft_catalog::safe_file::write_atomic_nosync`]: a temp file
+/// renamed into place), so a failure part-way leaves any previous file intact and no truncated
+/// one. Not synced to disk (issue #134): an export can always be made again from the original.
+/// The native writer behind exports, renders and screenshots (app, CLI, MCP).
 pub fn write_file(path: &str, bytes: &[u8]) -> Result<(), String> {
+    write_with(path, bytes, false)
+}
+
+/// [`write_file`], synced to disk: for a written file that becomes a library photo (Edit a Copy)
+/// and so can't simply be exported again once the catalog points at it.
+pub fn write_file_durable(path: &str, bytes: &[u8]) -> Result<(), String> {
+    write_with(path, bytes, true)
+}
+
+fn write_with(path: &str, bytes: &[u8], durable: bool) -> Result<(), String> {
+    use lightcraft_catalog::safe_file::{write_atomic, write_atomic_nosync};
     let p = std::path::Path::new(path);
     if let Some(dir) = p.parent().filter(|d| !d.as_os_str().is_empty()) {
         std::fs::create_dir_all(dir).map_err(|e| format!("{}: {e}", dir.display()))?;
     }
-    lightcraft_catalog::safe_file::write_atomic(p, bytes).map_err(|e| format!("{path}: {e}"))
+    if durable { write_atomic(p, bytes) } else { write_atomic_nosync(p, bytes) }.map_err(|e| format!("{path}: {e}"))
 }
 
 /// The path of the sidecar with extension `ext` of the exported file `main`.
@@ -1334,21 +1364,46 @@ mod tests {
         assert!(ExportOptions::from_json(&serde_json::json!({"watermark": ""})).watermark.is_none());
     }
 
-    #[test]
-    fn japanese_watermarks_support_vertical_columns_and_legacy_defaults() {
-        use ab_glyph::Font;
-        let font = ab_glyph::FontRef::try_from_slice(WATERMARK_JAPANESE_FONT).unwrap();
-        for c in "日本語".chars() {
-            assert_ne!(font.glyph_id(c).0, 0);
-        }
-        let old = ExportOptions::from_json(&json!({"watermark": {"text": "日本語"}}));
-        assert!(!old.watermark.unwrap().vertical);
+    fn vertical_japanese() -> Watermark {
         let options =
             ExportOptions::from_json(&json!({"watermark": {"text": "日本語", "vertical": true, "size": 0.1, "shadow": false, "opacity": 1.0}}));
-        let wm = options.watermark.unwrap();
+        options.watermark.unwrap()
+    }
+
+    #[test]
+    fn japanese_watermark_options_and_legacy_defaults() {
+        let old = ExportOptions::from_json(&json!({"watermark": {"text": "日本語"}}));
+        assert!(!old.watermark.unwrap().vertical);
+        let wm = vertical_japanese();
         assert!(wm.vertical);
         let round: Watermark = serde_json::from_value(serde_json::to_value(&wm).unwrap()).unwrap();
         assert!(round.vertical);
+    }
+
+    /// Built without craft-fonts, a Japanese watermark still lays out and draws (Inter's
+    /// missing-glyph boxes), and Latin text is unaffected.
+    #[test]
+    fn watermarks_work_without_craft_fonts() {
+        assert_eq!(watermark_fonts(&[]).len(), 1, "Inter only");
+        for wm in [vertical_japanese(), Watermark { text: "LightCraft 日本語".into(), ..Watermark::default() }] {
+            let mut covered = 0usize;
+            watermark_coverage(400, 300, &wm, &[], |_, _, k, _| covered += usize::from(k > 0.0));
+            assert!(covered > 0, "{:?} draws something", wm.text);
+        }
+    }
+
+    #[test]
+    fn japanese_watermarks_support_vertical_columns() {
+        use ab_glyph::Font;
+        let fonts = watermark_fonts(crate::fonts::CRAFT_FONTS);
+        if fonts.len() < 2 {
+            eprintln!("skipped: built without CRAFT_FONTS_DIR, so there is no Japanese watermark face");
+            return;
+        }
+        for c in "日本語の文字".chars() {
+            assert!(fonts[1..].iter().any(|f| f.glyph_id(c).0 != 0), "a craft-fonts face has {c}");
+        }
+        let wm = vertical_japanese();
         let mut img = Rgba8::new(400, 300);
         img.data.fill([0, 0, 0, 255]);
         draw_watermark(&mut img, &wm);

crates/engine/src/files.rs

@@ -38,6 +38,7 @@ fn meta_of(m: &lightcraft_meta::Metadata) -> (Meta, Option<String>) {
         copyright_url: m.copyright_url.clone().unwrap_or_default(),
         creator: m.artist.clone().unwrap_or_default(),
         keywords: m.keywords.clone(),
+        regions: m.regions.clone(),
     };
     (meta, m.capture_time.as_ref().map(|d| d.to_iso()))
 }
@@ -131,7 +132,9 @@ pub fn probe_bytes(name: &str, bytes: &[u8]) -> Result<ProbeInfo, String> {
             std::mem::swap(&mut w, &mut h);
         }
         let (t, tint) = xy_to_temp_tint(lightcraft_raw::color::as_shot_white_xy_of(&raw));
-        let as_shot_wb = Some((t.round(), tint.round()));
+        // Vendor RGB multipliers do not identify an absolute illuminant without camera calibration.
+        let relative = crate::camera_preview::file_local_look(raw.format) && !lightcraft_raw::color::has_matrix(&raw.color);
+        let as_shot_wb = Some(if relative { (6500.0, 0.0) } else { (t.round(), tint.round()) });
         let embedded_lens = embedded_lens(&raw);
         return Ok(ProbeInfo {
             embedded_lens,
@@ -221,6 +224,9 @@ fn load_bytes_now(bytes: std::borrow::Cow<'_, [u8]>, max_edge: usize) -> Result<
             }
             Err(e) => return Err(e.to_string()),
         };
+        let xy = lightcraft_raw::color::as_shot_white_xy(&raw);
+        let t = lightcraft_raw::color::camera_transform(&raw, xy);
+        let camera_look = crate::camera_preview::fit_preview(&raw, &bytes, &t);
         drop(bytes);
         // Embedded lens corrections are applied by the pipeline ("Enable Profile Corrections"), not baked in.
         let lens = embedded_lens(&raw.info());
@@ -242,21 +248,28 @@ fn load_bytes_now(bytes: std::borrow::Cow<'_, [u8]>, max_edge: usize) -> Result<
         // the samples aren't needed any more (the colour model below reads only the tags)
         raw.data = lightcraft_raw::RawData::U16(Vec::new());
         let mut stages = vec![("develop", t0.elapsed())];
-        let xy = lightcraft_raw::color::as_shot_white_xy(&raw);
-        let t = lightcraft_raw::color::camera_transform(&raw, xy);
         stages.push(("transform", t0.elapsed()));
         lightcraft_raw::highlight::reconstruct(&mut img, t.wb, HIGHLIGHT_CLIP);
         stages.push(("highlights", t0.elapsed()));
-        let m = t.matrix.to_f32();
+        let m = camera_look.as_ref().map(|p| p.matrix.mul(&t.matrix)).unwrap_or(t.matrix).to_f32();
+        let hue_sat = camera_look.as_ref().and_then(|p| p.hue_sat.as_ref()).and_then(crate::camera_preview::HueSat::new);
         let gain = 2f32.powf(t.baseline_exposure as f32);
         let wb = t.wb;
+        // A DNG's own profile look (hue/saturation map, look table), DNG spec chapter 6.
+        let tables = lightcraft_raw::profile::ProfileTables::new(&raw.color.profile, lightcraft_raw::color::illuminant_weight(&raw.color, xy));
         img.map_in_place(|p| {
             let c = [p[0] * wb[0], p[1] * wb[1], p[2] * wb[2]];
-            [
-                ((m[0][0] * c[0] + m[0][1] * c[1] + m[0][2] * c[2]) * gain).max(0.0),
-                ((m[1][0] * c[0] + m[1][1] * c[1] + m[1][2] * c[2]) * gain).max(0.0),
-                ((m[2][0] * c[0] + m[2][1] * c[1] + m[2][2] * c[2]) * gain).max(0.0),
-            ]
+            let rgb = [
+                m[0][0] * c[0] + m[0][1] * c[1] + m[0][2] * c[2],
+                m[1][0] * c[0] + m[1][1] * c[1] + m[1][2] * c[2],
+                m[2][0] * c[0] + m[2][1] * c[1] + m[2][2] * c[2],
+            ];
+            let rgb = match &tables {
+                Some(tables) => tables.apply(rgb, gain),
+                None => rgb.map(|v| v * gain),
+            };
+            // after the baseline exposure, as when it was fitted
+            hue_sat.as_ref().map_or(rgb, |h| h.apply(rgb)).map(|v| v.max(0.0))
         });
         stages.push(("colour", t0.elapsed()));
         let img = fit(&img, max_edge, max_edge, Filter::Box);
@@ -276,7 +289,10 @@ fn load_bytes_now(bytes: std::borrow::Cow<'_, [u8]>, max_edge: usize) -> Result<
             eprintln!("[profile] raw source {}×{} (max {max_edge}, ms after decode): {}", img.width, img.height, parts.join(", "));
         }
         let (temp, tint) = xy_to_temp_tint(xy);
-        return Ok((img, SourceInfo { raw: true, as_shot_temp: temp.round(), as_shot_tint: tint.round(), lens }));
+        let relative = crate::camera_preview::file_local_look(raw.format) && t.matrix_is_fallback;
+        let camera_tone = camera_look.as_ref().map(|p| p.tone).or_else(|| raw.color.profile.tone_curve.as_ref().and_then(dng_tone_curve));
+        let (temp, tint) = if relative { (6500.0, 0.0) } else { (temp.round(), tint.round()) };
+        return Ok((img, SourceInfo { raw: true, as_shot_temp: temp, as_shot_tint: tint, lens, relative_wb: relative, camera_tone }));
     }
     let d = lightcraft_codecs::decode(&bytes, lightcraft_codecs::DecodeOptions::fit(max_edge as u32, max_edge as u32)).map_err(|e| e.to_string())?;
     drop(bytes);
@@ -285,6 +301,17 @@ fn load_bytes_now(bytes: std::borrow::Cow<'_, [u8]>, max_edge: usize) -> Result<
     Ok((img.into_oriented(Orientation::from_exif(d.orientation)), SourceInfo::default()))
 }
 
+/// A DNG `ProfileToneCurve` (linear in, linear out, 1.0 = white after exposure compensation) as the
+/// finish stage's camera tone curve: 32 knots, log-spaced over 12 stops below white; above white
+/// the camera tone's shoulder continues it.
+pub(crate) fn dng_tone_curve(curve: &lightcraft_raw::profile::ToneCurve) -> Option<lightcraft_pipeline::tone::CameraTone> {
+    let knots: [[f32; 2]; 32] = std::array::from_fn(|i| {
+        let x = 2f32.powf(-12.0 + 12.0 * i as f32 / 31.0);
+        [x, curve.eval(x).min(0.9995)]
+    });
+    lightcraft_pipeline::tone::CameraTone::new(knots)
+}
+
 /// Orientation for an embedded preview: its own EXIF orientation when it has one, else the raw file's.
 fn preview_orientation(raw_bytes: &[u8], jpeg_orientation: u16) -> Orientation {
     if jpeg_orientation > 1 {
@@ -390,6 +417,41 @@ mod tests {
         b
     }
 
+    /// Issue #138: a DNG's own profile look (hue/saturation map, look table, tone curve) is
+    /// applied when it's developed — Lightroom-converted DNGs rendered flat and muted without it.
+    #[test]
+    fn dng_profile_look_is_applied() {
+        use lightcraft_raw::profile::{HsvTable, ProfileLook, ToneCurve};
+        let plain = crate::tests_xmp::synthetic_dng_with(None, Default::default());
+        let mut raw = lightcraft_raw::decode(&plain).unwrap();
+        let sat = |img: &Rgb32f| {
+            img.data.iter().map(|p| (p[0].max(p[1]).max(p[2]) - p[0].min(p[1]).min(p[2])) / p[0].max(p[1]).max(p[2]).max(1e-6)).sum::<f32>()
+                / img.data.len() as f32
+        };
+        let (before, info) = load_bytes(&plain, 64).unwrap();
+        assert!(sat(&before) > 0.05, "the synthetic scene is coloured");
+        assert!(info.camera_tone.is_none());
+        // a map that removes all saturation, and a tone curve
+        let grey = HsvTable { hue_divisions: 4, sat_divisions: 2, val_divisions: 1, data: vec![[0.0, 0.0, 1.0]; 8], srgb_value: false };
+        raw.color.profile =
+            ProfileLook { hue_sat_map: [Some(grey), None], look_table: None, tone_curve: ToneCurve::from_tag(&[0.0, 0.0, 0.18, 0.3, 1.0, 1.0]) };
+        let with = lightcraft_raw::write_dng(&raw, &Default::default()).unwrap();
+        let (after, info) = load_bytes(&with, 64).unwrap();
+        assert!(sat(&after) < 1e-3, "saturation {} → {}", sat(&before), sat(&after));
+        // a saturation-only map keeps brightness roughly (HSV value is kept in ProPhoto RGB)
+        let mean = |img: &Rgb32f| img.data.iter().map(|p| p[0].max(p[1]).max(p[2])).sum::<f32>() / img.data.len() as f32;
+        assert!((0.8..1.1).contains(&(mean(&after) / mean(&before))), "{} vs {}", mean(&after), mean(&before));
+        let tone = info.camera_tone.expect("the DNG tone curve becomes the camera tone");
+        assert!((tone.apply(0.18) - 0.3).abs() < 0.01, "{}", tone.apply(0.18));
+        // a look table alone changes the render too (applied after exposure)
+        raw.color.profile = ProfileLook {
+            look_table: Some(HsvTable { hue_divisions: 1, sat_divisions: 2, val_divisions: 1, data: vec![[0.0, 1.0, 0.5]; 2], srgb_value: false }),
+            ..Default::default()
+        };
+        let (dim, _) = load_bytes(&lightcraft_raw::write_dng(&raw, &Default::default()).unwrap(), 64).unwrap();
+        assert!((mean(&dim) / mean(&before) - 0.5).abs() < 0.02, "{} vs {}", mean(&dim), mean(&before));
+    }
+
     #[test]
     fn unsupported_raw_falls_back_to_embedded_preview() {
         let b = cr3_with_preview(48, 32);

crates/engine/src/fonts.rs

@@ -0,0 +1,115 @@
+//! Fonts from the optional craft-fonts build input (storytold/craft-fonts).
+//!
+//! Built with `CRAFT_FONTS_DIR=<craft-fonts checkout>`, [`CRAFT_FONTS`] holds every font in its
+//! manifest (today: the Japanese and Simplified-Chinese UI and document fonts); otherwise it is
+//! empty and LightCraft uses only its own bundled fonts (Inter). Both the egui UI and the export
+//! watermark renderer read it from here. See craftrules `standards/fonts.md`.
+
+/// A font from the optional craft-fonts build input (empty unless built with `CRAFT_FONTS_DIR`).
+pub struct CraftFont {
+    pub family: &'static str,
+    pub style: &'static str,
+    /// ISO 15924 scripts the font is for, e.g. `"Jpan"`.
+    pub scripts: &'static [&'static str],
+    pub bytes: &'static [u8],
+}
+
+include!(concat!(env!("OUT_DIR"), "/craft_fonts.rs"));
+
+impl CraftFont {
+    /// Whether the font is meant for `script` (ISO 15924, e.g. `"Jpan"`).
+    pub fn covers(&self, script: &str) -> bool {
+        self.scripts.contains(&script)
+    }
+
+    /// Mincho (serif) faces, the preferred Japanese faces for document-like text.
+    pub fn is_mincho(&self) -> bool {
+        self.family.contains("Mincho")
+    }
+
+    /// Whether the font can stand in for `script`: it is meant for it, or — until craft-fonts has a
+    /// Traditional Chinese face — it is a Simplified Chinese face, which carries the Traditional
+    /// characters too (with mainland glyph forms; still closer than the Japanese faces).
+    pub fn serves(&self, script: &str) -> bool {
+        self.covers(script) || (script == "Hant" && self.covers("Hans"))
+    }
+}
+
+/// The craft-fonts faces for Japanese, in `fonts`' order (empty without craft-fonts).
+pub fn japanese(fonts: &'static [CraftFont]) -> impl Iterator<Item = &'static CraftFont> {
+    fonts.iter().filter(|f| f.covers("Jpan"))
+}
+
+/// The craft-fonts faces for any CJK script: what any CJK text needs, regardless of language.
+pub fn cjk(fonts: &'static [CraftFont]) -> impl Iterator<Item = &'static CraftFont> {
+    fonts.iter().filter(|f| f.scripts.iter().any(|script| is_cjk_script(script)))
+}
+
+/// Whether an ISO 15924 script is written with Han, kana or hangul characters (Unicode's CJK
+/// scripts), which Inter has no glyphs for.
+pub fn is_cjk_script(script: &str) -> bool {
+    matches!(script, "Hans" | "Hant" | "Jpan" | "Kore" | "Hang" | "Hani" | "Bopo" | "Yiii" | "Nshu" | "Tang")
+}
+
+/// The craft-fonts faces to fall back on for `script`, in preference order: the faces of that script
+/// first (for `style` when asked), then every other CJK face. One CJK face list serves every
+/// language, but Han characters are shared between them: a Chinese reader must get the Chinese
+/// forms and a Japanese reader the Japanese ones, so the active language's own script comes first.
+/// Empty without craft-fonts.
+pub fn cjk_fallback<'a>(fonts: &'a [CraftFont], script: &str, style: &str) -> Vec<&'a CraftFont> {
+    let mut faces: Vec<&CraftFont> = fonts.iter().filter(|font| covers_cjk(font)).collect();
+    faces.sort_by_key(|font| {
+        (
+            // The language's own script first. A face dedicated to the script is preferred over a
+            // multi-script face (Noto Sans CJK SC claims `Hans,Latn`; a Japanese face claims `Jpan`).
+            !font.serves(script),
+            font.scripts.len() != 1,
+            font.family != "BIZ UDPGothic",
+            font.style != style,
+            font.is_mincho(),
+        )
+    });
+    faces
+}
+
+/// Whether the font is for any CJK script.
+fn covers_cjk(font: &CraftFont) -> bool {
+    font.scripts.iter().any(|script| is_cjk_script(script))
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn craft_fonts_are_well_formed_or_absent() {
+        if CRAFT_FONTS.is_empty() {
+            eprintln!("built without CRAFT_FONTS_DIR: no craft-fonts to check");
+            return;
+        }
+        for f in CRAFT_FONTS {
+            assert!(!f.family.is_empty() && !f.style.is_empty() && !f.scripts.is_empty(), "{}", f.family);
+            assert!(ab_glyph::FontRef::try_from_slice(f.bytes).is_ok(), "{} {} parses", f.family, f.style);
+        }
+        assert!(japanese(CRAFT_FONTS).next().is_some(), "craft-fonts carries Japanese faces");
+    }
+
+    /// Each language's own faces come first, so shared Han keeps the language's forms, and Latin
+    /// text still reaches Inter before any CJK fallback.
+    #[test]
+    fn a_language_gets_its_own_script_first() {
+        static FACES: &[CraftFont] = &[
+            CraftFont { family: "BIZ UDPGothic", style: "Regular", scripts: &["Jpan", "Latn"], bytes: &[] },
+            CraftFont { family: "Noto Sans CJK SC", style: "Regular", scripts: &["Hans", "Latn"], bytes: &[] },
+            CraftFont { family: "BIZ UDMincho", style: "Regular", scripts: &["Jpan", "Latn"], bytes: &[] },
+        ];
+        let first = |script: &str| cjk_fallback(FACES, script, "Regular").first().map(|f| f.family);
+        assert_eq!(first("Hans"), Some("Noto Sans CJK SC"));
+        assert_eq!(first("Jpan"), Some("BIZ UDPGothic"));
+        // No Traditional Chinese face yet: the Chinese face stands in before the Japanese ones.
+        assert_eq!(first("Hant"), Some("Noto Sans CJK SC"));
+        // Every CJK face is still offered to every language.
+        assert_eq!(cjk_fallback(FACES, "Hans", "Regular").len(), 3);
+        assert_eq!(cjk_fallback(&[], "Hans", "Regular").len(), 0);
+    }
+}

crates/engine/src/import.rs

@@ -375,13 +375,16 @@ fn probe_all(probe: Option<&crate::media::FileProbe>, paths: &[String], progress
 
 /// Copy `src` into `root`/`folders` as `name` (default: its own name), made unique with -1, -2…;
 /// returns the new path. The copy is verified ([`crate::import_move::copy_new`]: a new file,
-/// synced and compared byte for byte); a bad one is removed and the photo reported as failed.
-fn copy_into(root: &Path, src: &str, folders: &[String], name: Option<&str>) -> Result<String, String> {
+/// synced and checked against `probe_hash`, the content hash the probe computed — or compared
+/// byte for byte with the source when there is none); a bad one is removed and the photo
+/// reported as failed.
+fn copy_into(root: &Path, src: &str, folders: &[String], name: Option<&str>, probe_hash: Option<&str>) -> Result<String, String> {
     let dir = folders.iter().fold(root.to_path_buf(), |d, f| d.join(f));
     let name = name
         .map(str::to_string)
         .unwrap_or_else(|| Path::new(src).file_name().map(|n| n.to_string_lossy().to_string()).unwrap_or_else(|| "photo".into()));
-    crate::import_move::copy_new(Path::new(src), &dir, &name).map(|p| p.to_string_lossy().to_string())
+    let expect = probe_hash.and_then(lightcraft_preview::Hash128::parse);
+    crate::import_move::copy_new(Path::new(src), &dir, &name, expect).map(|p| p.to_string_lossy().to_string())
 }
 
 /// What a [`scan`] needs from the session, so it can run on another thread (a folder on a network
@@ -517,205 +520,392 @@ pub fn import(s: &mut Session, paths: &[String], mode: ImportMode) -> crate::Res
 }
 
 /// Import files/folders with options (preset, keywords). See the module docs.
+///
+/// The file-system half ([`ImportJob::prepare`]: expanding folders, probing, reading sidecars,
+/// copying / placing files) and the catalog half ([`commit_prepared`]) are separate so the app can
+/// run the first on a worker thread; here both run in turn.
 pub fn import_with(s: &mut Session, paths: &[String], opts: &ImportOptions) -> crate::Result<ImportReport> {
-    let mode = opts.mode;
-    // Only a library on disk has an `Originals/` folder. The browser build keeps the bytes of every
-    // added file in its own storage already, so "copy" there means "add".
-    let transfer = matches!(mode, ImportMode::Copy | ImportMode::Move);
-    let mode = if transfer && s.library.as_ref().is_some_and(|l| !l.on_disk) { ImportMode::Add } else { mode };
-    if mode == ImportMode::Move && opts.local {
-        return Err(crate::EngineError::Other("browsing a folder never moves its files".into()));
-    }
-    let lib_dir = s.library.as_ref().filter(|l| l.on_disk).map(|l| l.dir.clone());
-    // where copies go: the chosen folder, else the library's Originals/
-    let copy_root = opts
-        .destination
-        .as_deref()
-        .filter(|d| !d.trim().is_empty())
-        .map(std::path::PathBuf::from)
-        .or_else(|| lib_dir.as_ref().map(|l| l.join("Originals")));
-    if matches!(mode, ImportMode::Copy | ImportMode::Move) && copy_root.is_none() {
-        return Err(crate::EngineError::Other("copying or moving needs a destination folder or an open library".into()));
-    }
-    let mut seq = opts.rename_start.max(1);
-    let files = expand(paths, lib_dir.as_deref());
-    let mut report = ImportReport { scanned: files.len(), ..Default::default() };
+    let mut job = ImportJob::new(s, opts.clone())?;
+    let prepared = job.prepare(paths, &std::sync::atomic::AtomicBool::new(false));
+    // probes a scan left for files not imported now stay for a later import
+    s.import_probes.extend(std::mem::take(&mut job.cache));
+    commit_prepared(s, &job.opts, &job.now, prepared)
+}
 
-    // existing paths and content hashes
-    let mut by_path: HashMap<&str, PhotoId> = HashMap::new();
-    let mut by_hash: HashMap<String, PhotoId> = HashMap::new();
-    for p in s.catalog.photos() {
-        if let Source::File { path } = &p.source {
-            by_path.insert(path.as_str(), p.id);
-        }
-        if let Some(h) = &p.content_hash {
-            by_hash.insert(h.clone(), p.id);
-        }
-    }
-    let mut todo = Vec::new();
-    // a file that was only browsed (Local) joins the library when it is imported for real
-    let mut promote = Vec::new();
-    for f in files {
-        match by_path.get(f.as_str()) {
-            Some(id) if !opts.local && s.catalog.photo(*id).is_some_and(|p| p.local) => {
-                promote.push(Op::SetLocal { id: *id, local: false });
-                report.imported.push(id.0);
+/// Everything the file-system half of an import needs, detached from the session so it can run
+/// on another thread (a network share or a card can take minutes). Built by [`ImportJob::new`];
+/// [`ImportJob::prepare`] may be called for several batches in turn (renamed copies keep counting,
+/// duplicates are found across batches); each batch is then [`commit_prepared`] on the session.
+pub struct ImportJob {
+    pub opts: ImportOptions,
+    /// The mode in effect (Copy / Move become Add in a library without its own folder).
+    mode: ImportMode,
+    lib_dir: Option<PathBuf>,
+    copy_root: Option<PathBuf>,
+    /// path → (photo, a Local browse record?)
+    by_path: HashMap<String, (PhotoId, bool)>,
+    /// content hash → the photo that has it (`None`: a file earlier in this import)
+    by_hash: HashMap<String, Option<PhotoId>>,
+    probe: Option<crate::media::FileProbe>,
+    file_bytes: Option<crate::merge::ByteReader>,
+    /// Probes from a preceding scan (not read again).
+    cache: HashMap<String, ProbeInfo>,
+    naming: crate::sidecar::SidecarNaming,
+    now: String,
+    seq: usize,
+    /// Files found so far (folders expanded) and handled so far, for progress.
+    pub total: std::sync::Arc<std::sync::atomic::AtomicUsize>,
+    pub done: std::sync::Arc<std::sync::atomic::AtomicUsize>,
+}
+
+/// The outcome of [`ImportJob::prepare`] for one batch, in file order.
+#[derive(Debug, Default)]
+pub struct Prepared {
+    pub scanned: usize,
+    items: Vec<PreparedItem>,
+}
+
+#[derive(Debug)]
+enum PreparedItem {
+    /// A Local (browsed) record imported for real.
+    Promote(PhotoId),
+    Duplicate {
+        path: String,
+        existing: Option<PhotoId>,
+        reason: &'static str,
+        hash: Option<String>,
+    },
+    Failed(String, String),
+    Kept(Kept),
+    Ready(Box<ReadyFile>),
+}
+
+#[derive(Debug)]
+struct ReadyFile {
+    path: String,
+    stored: String,
+    info: ProbeInfo,
+    sidecar: Option<crate::sidecar::SidecarData>,
+    placed: Option<crate::import_move::Placed>,
+}
+
+impl Prepared {
+    /// Undo what the batch did on disk that only a commit would make permanent: files placed by a
+    /// Move (their sources were never touched). Copies stay, like copies of a failed commit.
+    pub fn rollback(&self) {
+        for it in &self.items {
+            if let PreparedItem::Ready(r) = it
+                && let Some(pl) = &r.placed
+            {
+                crate::import_move::rollback(pl);
             }
-            Some(id) => report.duplicates.push(Duplicate { path: f, existing: Some(id.0), reason: "path" }),
-            None => todo.push(f),
         }
     }
 
-    // files a preceding scan already probed are not read again (a network share is slow to read)
-    let cached: Vec<Option<ProbeInfo>> = todo.iter().map(|f| s.import_probes.remove(f)).collect();
-    let missing: Vec<String> = todo.iter().zip(&cached).filter(|(_, c)| c.is_none()).map(|(f, _)| f.clone()).collect();
-    let mut fresh = probe_all(s.media.file_probe.as_ref(), &missing, &ScanProgress::default()).into_iter();
-    let probed: Vec<Result<ProbeInfo, String>> =
-        cached.into_iter().map(|c| c.map(Ok).unwrap_or_else(|| fresh.next().unwrap_or_else(|| Err("not probed".into())))).collect();
-    crate::memory::release();
-    let now = (s.clock)();
-    let mut ops = promote;
-    // Move: placed at the destination, sources untouched until the records are committed
-    let mut placed: Vec<crate::import_move::Placed> = Vec::new();
-    for (path, info) in todo.into_iter().zip(probed) {
-        let info = match info {
-            Ok(i) => i,
-            Err(e) => {
-                log::warn!("import {path}: {e}");
-                report.failed.push((path, e));
+    /// Entries in the batch (after expanding folders).
+    pub fn len(&self) -> usize {
+        self.items.len()
+    }
+
+    pub fn is_empty(&self) -> bool {
+        self.items.is_empty()
+    }
+}
+
+impl ImportJob {
+    /// Snapshot what an import with `opts` needs from the session (no file-system calls). Takes
+    /// the probes a preceding scan left ([`Session::import_probes`]).
+    pub fn new(s: &mut Session, opts: ImportOptions) -> crate::Result<Self> {
+        let mode = opts.mode;
+        // Only a library on disk has an `Originals/` folder. The browser build keeps the bytes of
+        // every added file in its own storage already, so "copy" there means "add".
+        let transfer = matches!(mode, ImportMode::Copy | ImportMode::Move);
+        let mode = if transfer && s.library.as_ref().is_some_and(|l| !l.on_disk) { ImportMode::Add } else { mode };
+        if mode == ImportMode::Move && opts.local {
+            return Err(crate::EngineError::Other("browsing a folder never moves its files".into()));
+        }
+        let lib_dir = s.library.as_ref().filter(|l| l.on_disk).map(|l| l.dir.clone());
+        // where copies go: the chosen folder, else the library's Originals/
+        let copy_root = opts
+            .destination
+            .as_deref()
+            .filter(|d| !d.trim().is_empty())
+            .map(std::path::PathBuf::from)
+            .or_else(|| lib_dir.as_ref().map(|l| l.join("Originals")));
+        if matches!(mode, ImportMode::Copy | ImportMode::Move) && copy_root.is_none() {
+            return Err(crate::EngineError::Other("copying or moving needs a destination folder or an open library".into()));
+        }
+        let mut by_path = HashMap::new();
+        let mut by_hash = HashMap::new();
+        for p in s.catalog.photos() {
+            if let Source::File { path } = &p.source {
+                by_path.insert(path.clone(), (p.id, p.local));
+            }
+            if let Some(h) = &p.content_hash {
+                by_hash.insert(h.clone(), Some(p.id));
+            }
+        }
+        Ok(ImportJob {
+            seq: opts.rename_start.max(1),
+            opts,
+            mode,
+            lib_dir,
+            copy_root,
+            by_path,
+            by_hash,
+            probe: s.media.file_probe.clone(),
+            file_bytes: s.media.file_bytes.clone(),
+            cache: std::mem::take(&mut s.import_probes),
+            naming: s.xmp.naming,
+            now: (s.clock)(),
+            total: Default::default(),
+            done: Default::default(),
+        })
+    }
+
+    /// The file-system half of importing `paths`: expand folders, skip known paths, probe, skip
+    /// duplicates by content, read sidecars, copy or place (Move) the files. Nothing in the
+    /// catalog changes. Stops before the next file once `cancel` is set.
+    pub fn prepare(&mut self, paths: &[String], cancel: &std::sync::atomic::AtomicBool) -> Prepared {
+        let files = self.expand(paths);
+        self.prepare_files(files, cancel)
+    }
+
+    /// Expand `paths` (folders recursively, the library's own folder skipped) into the files an
+    /// import would handle; counted in [`ImportJob::total`].
+    pub fn expand(&self, paths: &[String]) -> Vec<String> {
+        let files = expand(paths, self.lib_dir.as_deref());
+        self.total.fetch_add(files.len(), std::sync::atomic::Ordering::Relaxed);
+        files
+    }
+
+    /// When the import started ([`Session::clock`]), for [`commit_prepared`].
+    pub fn now(&self) -> &str {
+        &self.now
+    }
+
+    /// [`ImportJob::prepare`] for files [`ImportJob::expand`] returned.
+    pub fn prepare_files(&mut self, files: Vec<String>, cancel: &std::sync::atomic::AtomicBool) -> Prepared {
+        use std::sync::atomic::Ordering::Relaxed;
+        let opts = self.opts.clone();
+        let mode = self.mode;
+        let mut out = Prepared { scanned: files.len(), items: Vec::new() };
+        let mut todo = Vec::new();
+        for f in files {
+            match self.by_path.get(f.as_str()).copied() {
+                Some((id, true)) if !opts.local => {
+                    // a file that was only browsed (Local) joins the library when it is imported for real
+                    self.by_path.insert(f, (id, false));
+                    out.items.push(PreparedItem::Promote(id));
+                    self.done.fetch_add(1, Relaxed);
+                }
+                Some((id, _)) => {
+                    out.items.push(PreparedItem::Duplicate { path: f, existing: Some(id), reason: "path", hash: None });
+                    self.done.fetch_add(1, Relaxed);
+                }
+                None => todo.push(f),
+            }
+        }
+
+        // files a preceding scan already probed are not read again (a network share is slow to read)
+        let cached: Vec<Option<ProbeInfo>> = todo.iter().map(|f| self.cache.remove(f)).collect();
+        let missing: Vec<String> = todo.iter().zip(&cached).filter(|(_, c)| c.is_none()).map(|(f, _)| f.clone()).collect();
+        let progress = ScanProgress::default();
+        let mut fresh = probe_all(self.probe.as_ref(), &missing, &progress).into_iter();
+        let probed: Vec<Result<ProbeInfo, String>> =
+            cached.into_iter().map(|c| c.map(Ok).unwrap_or_else(|| fresh.next().unwrap_or_else(|| Err("not probed".into())))).collect();
+        crate::memory::release();
+        for (path, info) in todo.into_iter().zip(probed) {
+            if cancel.load(Relaxed) {
+                break;
+            }
+            self.done.fetch_add(1, Relaxed);
+            let mut info = match info {
+                Ok(i) => i,
+                Err(e) => {
+                    log::warn!("import {path}: {e}");
+                    out.items.push(PreparedItem::Failed(path, e));
+                    continue;
+                }
+            };
+            if let Some(h) = &info.content_hash
+                && !opts.local
+                && let Some(existing) = self.by_hash.get(h)
+            {
+                out.items.push(PreparedItem::Duplicate { path, existing: *existing, reason: "content", hash: Some(h.clone()) });
                 continue;
             }
-        };
-        if let Some(h) = &info.content_hash
-            && !opts.local
-            && let Some(id) = by_hash.get(h)
-        {
-            report.duplicates.push(Duplicate { path, existing: Some(id.0), reason: "content" });
-            continue;
-        }
-        // the XMP sidecar (or a raw's embedded XMP), read before copying: its capture time files
-        // and names the copy when the file itself has none
-        let raw = info.kind == MediaKind::Raw;
-        let packet = crate::sidecar::find_sidecar(&path, s.xmp.naming)
-            .and_then(|f| std::fs::read_to_string(f).ok())
-            .or_else(|| info.xmp.clone().filter(|_| raw));
-        let sidecar = packet.and_then(|x| match crate::sidecar::parse_sidecar(&x, raw).map(|sc| sc.resolve_label(&s.catalog)) {
-            Ok(sc) => (sc != crate::sidecar::SidecarData::default()).then_some(sc),
-            Err(e) => {
-                log::warn!("import {path}: XMP: {e}");
-                None
+            // the XMP sidecar (or a raw's embedded XMP), read before copying: its capture time files
+            // and names the copy when the file itself has none
+            let raw = info.kind == MediaKind::Raw;
+            let packet = crate::sidecar::find_sidecar(&path, self.naming)
+                .and_then(|f| std::fs::read_to_string(f).ok())
+                .or_else(|| info.xmp.clone().filter(|_| raw));
+            let sidecar = packet.and_then(|x| match crate::sidecar::parse_sidecar(&x, raw) {
+                Ok(sc) => Some(sc),
+                Err(e) => {
+                    log::warn!("import {path}: XMP: {e}");
+                    None
+                }
+            });
+            if info.captured.is_none() {
+                info.captured = sidecar.as_ref().and_then(|sc| sc.captured.clone());
             }
-        });
-        let mut info = info;
-        if info.captured.is_none() {
-            info.captured = sidecar.as_ref().and_then(|sc| sc.captured.clone());
-        }
-        let stored = match (mode, &copy_root) {
-            (ImportMode::Copy | ImportMode::Move, Some(root))
-                if !crate::import_move::inside(Path::new(&path), root)
-                    && !lib_dir.as_ref().is_some_and(|l| crate::import_move::inside(Path::new(&path), l)) =>
+            let mut placed = None;
+            let stored = match (mode, &self.copy_root) {
+                (ImportMode::Copy | ImportMode::Move, Some(root))
+                    if !crate::import_move::inside(Path::new(&path), root)
+                        && !self.lib_dir.as_ref().is_some_and(|l| crate::import_move::inside(Path::new(&path), l)) =>
+                {
+                    // the templates see the photo as it will be catalogued (undated: the import time)
+                    let own = Path::new(&path).file_name().map(|n| n.to_string_lossy().to_string()).unwrap_or_default();
+                    let mut q = Photo::new(PhotoId(0), Source::File { path: path.clone() }, &own, &info.format, 0, 0, &self.now);
+                    q.captured = info.captured.clone();
+                    q.meta = info.meta.clone();
+                    let name = opts.rename.as_deref().filter(|t| !t.trim().is_empty()).map(|t| {
+                        let n = crate::rename::expand(t, &q, self.seq);
+                        self.seq += 1;
+                        n
+                    });
+                    let folders = opts.organize.folders(&q);
+                    if mode == ImportMode::Move && !crate::import_move::is_symlink(Path::new(&path)) {
+                        let dir = folders.iter().fold(root.to_path_buf(), |d, f| d.join(f));
+                        let name = name.unwrap_or(own);
+                        match crate::import_move::place(Path::new(&path), &dir, &name) {
+                            Ok(pl) => {
+                                let dst = pl.dst.to_string_lossy().to_string();
+                                placed = Some(pl);
+                                dst
+                            }
+                            Err(e) => {
+                                out.items.push(PreparedItem::Failed(path, e));
+                                continue;
+                            }
+                        }
+                    } else {
+                        if mode == ImportMode::Move {
+                            let reason = "a symbolic link: the file it points to was copied, the link and its target stay";
+                            out.items.push(PreparedItem::Kept(Kept { path: path.clone(), reason: reason.into() }));
+                        }
+                        match copy_into(root, &path, &folders, name.as_deref(), info.content_hash.as_deref()) {
+                            Ok(p) => p,
+                            Err(e) => {
+                                out.items.push(PreparedItem::Failed(path, e));
+                                continue;
+                            }
+                        }
+                    }
+                }
+                (ImportMode::Move, _) => {
+                    let reason = "already inside the destination or the library: added where it is";
+                    out.items.push(PreparedItem::Kept(Kept { path: path.clone(), reason: reason.into() }));
+                    path.clone()
+                }
+                _ => path.clone(),
+            };
+            if let Some(h) = &info.content_hash {
+                self.by_hash.insert(h.clone(), None);
+            }
+            // Copy as DNG: the copied raw becomes a DNG (the copy is ours to replace)
+            let mut stored = stored;
+            if opts.convert_dng
+                && mode == ImportMode::Copy
+                && stored != path
+                && info.kind == MediaKind::Raw
+                && !info.format.eq_ignore_ascii_case("DNG")
             {
-                // the templates see the photo as it will be catalogued (undated: the import time)
-                let own = Path::new(&path).file_name().map(|n| n.to_string_lossy().to_string()).unwrap_or_default();
-                let mut q = Photo::new(PhotoId(0), Source::File { path: path.clone() }, &own, &info.format, 0, 0, &now);
-                q.captured = info.captured.clone();
-                q.meta = info.meta.clone();
-                let name = opts.rename.as_deref().filter(|t| !t.trim().is_empty()).map(|t| {
-                    let n = crate::rename::expand(t, &q, seq);
-                    seq += 1;
-                    n
+                match crate::cmd::convert::write_dng_with(self.file_bytes.as_ref(), &stored, String::new()) {
+                    Ok(dng) => {
+                        let _ = std::fs::remove_file(&stored);
+                        stored = dng;
+                        info.format = "DNG".into();
+                    }
+                    Err(e) => log::warn!("import {path}: copy as DNG: {e}"),
+                }
+            }
+            out.items.push(PreparedItem::Ready(Box::new(ReadyFile { path, stored, info, sidecar, placed })));
+        }
+        out
+    }
+}
+
+/// The catalog half of an import: add the photos [`ImportJob::prepare`] readied (one undoable op;
+/// a Move's sources are removed once it is saved). On a failed commit a Move's placed files are
+/// taken back.
+pub fn commit_prepared(s: &mut Session, opts: &ImportOptions, now: &str, prepared: Prepared) -> crate::Result<ImportReport> {
+    let now = now.to_string();
+    let mut report = ImportReport { scanned: prepared.scanned, ..Default::default() };
+    let mut ops = Vec::new();
+    // Move: placed at the destination, sources untouched until the records are committed
+    let mut placed: Vec<crate::import_move::Placed> = Vec::new();
+    // photos added by this batch, by content (a duplicate of a file earlier in the import names it)
+    let mut new_hash: HashMap<String, PhotoId> = HashMap::new();
+    for it in prepared.items {
+        match it {
+            PreparedItem::Promote(id) => {
+                if s.catalog.photo(id).is_some_and(|p| p.local) {
+                    ops.push(Op::SetLocal { id, local: false });
+                }
+                report.imported.push(id.0);
+            }
+            PreparedItem::Duplicate { path, existing, reason, hash } => {
+                let existing = existing.or_else(|| {
+                    let h = hash?;
+                    new_hash.get(&h).copied().or_else(|| s.catalog.photos().find(|p| p.content_hash.as_deref() == Some(h.as_str())).map(|p| p.id))
                 });
-                let folders = opts.organize.folders(&q);
-                if mode == ImportMode::Move && !crate::import_move::is_symlink(Path::new(&path)) {
-                    let dir = folders.iter().fold(root.to_path_buf(), |d, f| d.join(f));
-                    let name = name.unwrap_or(own);
-                    match crate::import_move::place(Path::new(&path), &dir, &name) {
-                        Ok(pl) => {
-                            let dst = pl.dst.to_string_lossy().to_string();
-                            placed.push(pl);
-                            dst
-                        }
-                        Err(e) => {
-                            report.failed.push((path, e));
-                            continue;
-                        }
-                    }
-                } else {
-                    if mode == ImportMode::Move {
-                        let reason = "a symbolic link: the file it points to was copied, the link and its target stay";
-                        report.kept.push(Kept { path: path.clone(), reason: reason.into() });
-                    }
-                    match copy_into(root, &path, &folders, name.as_deref()) {
-                        Ok(p) => p,
-                        Err(e) => {
-                            report.failed.push((path, e));
-                            continue;
-                        }
+                report.duplicates.push(Duplicate { path, existing: existing.map(|i| i.0), reason });
+            }
+            PreparedItem::Failed(path, e) => report.failed.push((path, e)),
+            PreparedItem::Kept(k) => report.kept.push(k),
+            PreparedItem::Ready(r) => {
+                let ReadyFile { path, stored, info, sidecar, placed: pl } = *r;
+                placed.extend(pl);
+                let id = s.catalog.alloc_photo_id();
+                if let Some(h) = &info.content_hash {
+                    new_hash.insert(h.clone(), id);
+                }
+                let sidecar = sidecar.map(|sc| sc.resolve_label(&s.catalog)).filter(|sc| *sc != crate::sidecar::SidecarData::default());
+                // a copy is catalogued under its new name
+                let name = Path::new(&stored).file_name().map(|n| n.to_string_lossy().to_string()).unwrap_or_else(|| path.clone());
+                let mut p = Photo::new(id, Source::File { path: stored }, &name, &info.format, info.width, info.height, &now);
+                p.kind = info.kind;
+                p.file_size = info.file_size;
+                p.captured = info.captured;
+                p.meta = info.meta;
+                p.as_shot_wb = info.as_shot_wb;
+                p.content_hash = info.content_hash;
+                p.embedded_lens = info.embedded_lens;
+                p.preview_only = info.preview_only.clone();
+                apply_import_defaults(s, &mut p);
+                if let Some(sc) = &sidecar {
+                    crate::sidecar::merge_into(&mut p, sc, &now);
+                    report.sidecars += 1;
+                }
+                if let Some(mp) = opts.metadata_preset.as_ref().and_then(|n| s.metadata_presets.iter().find(|m| m.name.eq_ignore_ascii_case(n))) {
+                    crate::cmd::metadata::apply_to(&mut p.meta, &mp.fields);
+                }
+                for k in &opts.keywords {
+                    let k = lightcraft_catalog::keywords::clean(k);
+                    if !k.is_empty() && !p.meta.keywords.iter().any(|x| x.eq_ignore_ascii_case(&k)) {
+                        p.meta.keywords.push(k);
                     }
                 }
-            }
-            (ImportMode::Move, _) => {
-                let reason = "already inside the destination or the library: added where it is";
-                report.kept.push(Kept { path: path.clone(), reason: reason.into() });
-                path.clone()
-            }
-            _ => path.clone(),
-        };
-        let id = s.catalog.alloc_photo_id();
-        if let Some(h) = &info.content_hash {
-            by_hash.insert(h.clone(), id);
-        }
-        // Copy as DNG: the copied raw becomes a DNG (the copy is ours to replace)
-        let mut stored = stored;
-        if opts.convert_dng && mode == ImportMode::Copy && stored != path && info.kind == MediaKind::Raw && !info.format.eq_ignore_ascii_case("DNG") {
-            match crate::cmd::convert::write_dng_for(s, &stored, String::new()) {
-                Ok(dng) => {
-                    let _ = std::fs::remove_file(&stored);
-                    stored = dng;
-                    info.format = "DNG".into();
+                if let Some(preset) = &opts.preset {
+                    let d = std::sync::Arc::new(preset.apply(&p.develop, 1.0));
+                    let label = format!("Preset: {}", preset.name);
+                    p.develop = d.clone();
+                    p.edited = Some(now.clone());
+                    p.history.push(lightcraft_catalog::HistoryStep { label, settings: d });
                 }
-                Err(e) => log::warn!("import {path}: copy as DNG: {e}"),
+                report.imported.push(id.0);
+                p.local = opts.local;
+                if opts.local {
+                    // the state as browsed: a later change keeps the record from being forgotten
+                    p.set_local_baseline();
+                }
+                ops.push(Op::AddPhoto { photo: Box::new(p) });
             }
         }
-        // a copy is catalogued under its new name
-        let name = Path::new(&stored).file_name().map(|n| n.to_string_lossy().to_string()).unwrap_or_else(|| path.clone());
-        let mut p = Photo::new(id, Source::File { path: stored }, &name, &info.format, info.width, info.height, &now);
-        p.kind = info.kind;
-        p.file_size = info.file_size;
-        p.captured = info.captured;
-        p.meta = info.meta;
-        p.as_shot_wb = info.as_shot_wb;
-        p.content_hash = info.content_hash;
-        p.embedded_lens = info.embedded_lens;
-        p.preview_only = info.preview_only.clone();
-        apply_import_defaults(s, &mut p);
-        if let Some(sc) = &sidecar {
-            crate::sidecar::merge_into(&mut p, sc, &now);
-            report.sidecars += 1;
-        }
-        if let Some(mp) = opts.metadata_preset.as_ref().and_then(|n| s.metadata_presets.iter().find(|m| m.name.eq_ignore_ascii_case(n))) {
-            crate::cmd::metadata::apply_to(&mut p.meta, &mp.fields);
-        }
-        for k in &opts.keywords {
-            let k = lightcraft_catalog::keywords::clean(k);
-            if !k.is_empty() && !p.meta.keywords.iter().any(|x| x.eq_ignore_ascii_case(&k)) {
-                p.meta.keywords.push(k);
-            }
-        }
-        if let Some(preset) = &opts.preset {
-            let d = std::sync::Arc::new(preset.apply(&p.develop, 1.0));
-            let label = format!("Preset: {}", preset.name);
-            p.develop = d.clone();
-            p.edited = Some(now.clone());
-            p.history.push(lightcraft_catalog::HistoryStep { label, settings: d });
-        }
-        report.imported.push(id.0);
-        p.local = opts.local;
-        if opts.local {
-            // the state as browsed: a later change keeps the record from being forgotten
-            p.set_local_baseline();
-        }
-        ops.push(Op::AddPhoto { photo: Box::new(p) });
     }
     let log0 = s.pending_log.len();
     if !ops.is_empty()

crates/engine/src/import_move.rs

@@ -171,9 +171,15 @@ pub(crate) fn place(src: &Path, dir: &Path, name: &str) -> Result<Placed, String
 
 /// Import → **Copy**: copy `src` into `dir` as `name` (-1, -2… when taken) with the same checks as
 /// a move's copy — a new file (never overwriting one, even one that appears meanwhile), synced to
-/// disk and compared byte for byte with the source; a bad copy is removed and reported, so a card
-/// is never wiped on the strength of it. Returns the new path.
-pub(crate) fn copy_new(src: &Path, dir: &Path, name: &str) -> Result<PathBuf, String> {
+/// disk and verified; a bad copy is removed and reported, so a card is never wiped on the strength
+/// of it. Returns the new path.
+///
+/// `expect` is the content hash the import's probe computed from its full read of the source
+/// ([`lightcraft_preview::hash_bytes`]): the copy is read back and checked against it, which spares
+/// a third read of the card (issue #134). It also catches a source that changed since the probe
+/// (whose recorded metadata and hash would be stale). Without one the copy is compared byte for
+/// byte with the source.
+pub(crate) fn copy_new(src: &Path, dir: &Path, name: &str, expect: Option<lightcraft_preview::Hash128>) -> Result<PathBuf, String> {
     fs::create_dir_all(dir).map_err(|e| format!("{}: {e}", dir.display()))?;
     let (stem, ext) = match name.rsplit_once('.') {
         Some((s, e)) if !s.is_empty() => (s.to_string(), format!(".{e}")),
@@ -181,7 +187,7 @@ pub(crate) fn copy_new(src: &Path, dir: &Path, name: &str) -> Result<PathBuf, St
     };
     for i in 0..100_000u32 {
         let d = if i == 0 { dir.join(name) } else { dir.join(format!("{stem}-{i}{ext}")) };
-        match copy_verified(src, &d) {
+        match copy_verified(src, &d, expect) {
             Ok(()) => return Ok(d),
             Err(e) if e.kind() == io::ErrorKind::AlreadyExists => continue,
             Err(e) => return Err(format!("copy {}: {e} (nothing was imported from it; the original is untouched)", src.display())),
@@ -262,12 +268,14 @@ fn link_or_copy(src: &Path, dst: &Path) -> io::Result<()> {
             Err(_) => {}
         }
     }
-    copy_verified(src, dst)
+    // Move keeps the byte-for-byte comparison: the source is deleted on the strength of it
+    copy_verified(src, dst, None)
 }
 
-/// Copy into a new file, sync it to disk and compare it with the original; on any failure the
-/// partial copy is removed.
-fn copy_verified(src: &Path, dst: &Path) -> io::Result<()> {
+/// Copy into a new file, sync it to disk and verify it: against `expect` (the probe's hash of the
+/// source) when given, else byte for byte against the source. On any failure the partial copy is
+/// removed.
+pub(crate) fn copy_verified(src: &Path, dst: &Path, expect: Option<lightcraft_preview::Hash128>) -> io::Result<()> {
     let mut out = OpenOptions::new().write(true).create_new(true).open(dst)?;
     let r = (|| {
         let mut inp = File::open(src)?;
@@ -283,10 +291,14 @@ fn copy_verified(src: &Path, dst: &Path) -> io::Result<()> {
         if let Ok(m) = fs::metadata(src).and_then(|m| m.modified()) {
             let _ = out.set_modified(m);
         }
-        if !same_bytes(src, dst)? {
-            return Err(io::Error::other("the copy differs from the original"));
+        match expect {
+            Some(h) if hash_file(dst)? != h => {
+                Err(io::Error::other("the copy differs from the original as it was read for the import (a bad copy, or the file changed meanwhile)"))
+            }
+            Some(_) => Ok(()),
+            None if !same_bytes(src, dst)? => Err(io::Error::other("the copy differs from the original")),
+            None => Ok(()),
         }
-        Ok(())
     })();
     drop(out);
     if r.is_err() {
@@ -295,6 +307,20 @@ fn copy_verified(src: &Path, dst: &Path) -> io::Result<()> {
     r
 }
 
+/// [`lightcraft_preview::hash_bytes`] of a file's content, read in chunks.
+fn hash_file(path: &Path) -> io::Result<lightcraft_preview::Hash128> {
+    let mut f = File::open(path)?;
+    let mut h = lightcraft_preview::Hasher128::new();
+    let mut buf = vec![0u8; 1 << 20];
+    loop {
+        let n = fill(&mut f, &mut buf)?;
+        if n == 0 {
+            return Ok(h.finish());
+        }
+        h.update(buf.get(..n).unwrap_or(&[]));
+    }
+}
+
 /// Do two files hold the same bytes?
 pub(crate) fn same_bytes(a: &Path, b: &Path) -> io::Result<bool> {
     if fs::metadata(a)?.len() != fs::metadata(b)?.len() {

crates/engine/src/lib.rs

@@ -10,6 +10,9 @@
 //! run them off the UI thread.
 #![forbid(unsafe_code)]
 
+pub mod availability;
+mod camera_preview;
+pub mod camera_profiles;
 pub mod cmd;
 pub mod crs;
 pub mod crs_masks;
@@ -17,6 +20,7 @@ pub mod demo;
 pub mod devices;
 pub mod export;
 pub mod files;
+pub mod fonts;
 pub mod guard;
 pub mod import;
 mod import_move;
@@ -29,6 +33,7 @@ pub mod preset_import;
 pub mod preset_luminar;
 pub mod presets;
 pub mod rename;
+pub mod segment;
 pub mod sidecar;
 pub mod smart;
 mod view;
@@ -36,6 +41,7 @@ mod view;
 use std::sync::Arc;
 
 pub use cmd::{CommandInfo, CommandSpec, command_specs, find_command};
+pub use fonts::{CRAFT_FONTS, CraftFont};
 use lightcraft_catalog::{Catalog, Filter, Op, PhotoId, Sort};
 use lightcraft_develop::DevelopSettings;
 pub use media::{RenderJob, SourceLevel};
@@ -121,6 +127,9 @@ pub struct Session {
     pub undo: Vec<UndoEntry>,
     pub redo: Vec<UndoEntry>,
     pub interaction: Option<Interaction>,
+    /// Set by a command whose change must not rewrite the photo's XMP sidecar even with auto-write on
+    /// (a catalog-only edit of data the sidecar writer does not emit); consumed when the command ends.
+    pub(crate) skip_auto_write: bool,
     /// Copied develop settings (partial JSON) for Paste.
     pub clipboard: Option<Value>,
     /// The folder on disk the [`LibrarySource::Folder`] view browses.
@@ -146,6 +155,8 @@ pub struct Session {
     depth: u32,
     /// Selected mask (Masking panel), by mask id.
     pub active_mask: Option<u32>,
+    /// AI masks (SAM 3): the model and the last photo prepared for it.
+    pub segmenter: segment::Segmenter,
     /// Selected spot (Remove panel), by index into the active photo's spots.
     pub active_spot: Option<usize>,
     /// The persistent library this session writes to (`None` = in-memory only).
@@ -219,6 +230,7 @@ impl Session {
             undo: Vec::new(),
             redo: Vec::new(),
             interaction: None,
+            skip_auto_write: false,
             clipboard: None,
             meta_clipboard: None,
             browse: None,
@@ -233,6 +245,7 @@ impl Session {
             clock: Box::new(|| "2026-09-30T12:00:00".to_string()),
             depth: 0,
             active_mask: None,
+            segmenter: segment::Segmenter::default(),
             active_spot: None,
             library: None,
             xmp: sidecar::XmpPrefs::default(),
@@ -272,11 +285,22 @@ impl Session {
         (spec.enabled)(self).map_err(|why| EngineError::Disabled(id.to_string(), why))?;
         let empty = Value::Object(Default::default());
         let params = if params.is_null() { &empty } else { params };
+        self.run_command(id, spec.journal.then_some(params), |s| (spec.run)(s, params))
+    }
+
+    /// Run `f` as command `id` with what [`Session::execute`] does around every command: the
+    /// panic guard, auto versions, XMP sidecar auto-write and the durable save (a failed save is
+    /// `NotSaved`). Not journaled. The app's import task commits its batches this way.
+    pub fn execute_fn(&mut self, id: &str, f: impl FnOnce(&mut Session) -> Result<Value>) -> Result<Value> {
+        self.run_command(id, None, f)
+    }
+
+    fn run_command(&mut self, id: &str, journal: Option<&Value>, f: impl FnOnce(&mut Session) -> Result<Value>) -> Result<Value> {
         let log_start = self.pending_log.len();
         let was_active = self.active();
         self.depth += 1;
         // last-resort guard: a panic in a command is that command's error, not a crash
-        let r = guard::catch(&format!("`{id}`"), || (spec.run)(self, params)).unwrap_or_else(|e| Err(EngineError::Other(e)));
+        let r = guard::catch(&format!("`{id}`"), || f(self)).unwrap_or_else(|e| Err(EngineError::Other(e)));
         self.depth -= 1;
         if self.depth == 0 && was_active.is_some() && self.active() != was_active {
             self.previous_active = was_active;
@@ -284,14 +308,20 @@ impl Session {
                 self.auto_version(left);
             }
         }
-        if r.is_ok() && spec.journal && self.depth == 0 {
+        if r.is_ok()
+            && let Some(params) = journal
+            && self.depth == 0
+        {
             self.journal.push((id.to_string(), params.clone()));
             if self.journal.len() > 10_000 {
                 self.journal.drain(..1000);
             }
         }
-        if r.is_ok() && self.depth == 0 && self.xmp.auto_write && self.interaction.is_none() && self.pending_log.len() > log_start {
-            self.auto_write_sidecars(&self.pending_log[log_start..]);
+        if self.depth == 0 {
+            let skip = std::mem::take(&mut self.skip_auto_write);
+            if r.is_ok() && !skip && self.xmp.auto_write && self.interaction.is_none() && self.pending_log.len() > log_start {
+                self.auto_write_sidecars(&self.pending_log[log_start..]);
+            }
         }
         if self.depth == 0 && self.library.is_some() {
             // Make the command durable before reporting success. When the command's own records
@@ -560,7 +590,11 @@ impl Session {
 
     /// Photos shown in the grid/filmstrip for the current source, filter and sort.
     pub fn visible(&mut self) -> &[PhotoId] {
-        let key = (self.catalog.revision, format!("{:?}|{:?}|{:?}|{:?}", self.source, self.filter, self.sort, self.browse));
+        let mut key = (self.catalog.revision, format!("{:?}|{:?}|{:?}|{:?}", self.source, self.filter, self.sort, self.browse));
+        if self.source == LibrarySource::Missing && self.media.availability.is_background() {
+            // the view fills in as the background checks find files gone
+            key.1.push_str(&format!("|{}", self.media.availability.generation()));
+        }
         if self.visible_key.as_ref() != Some(&key) {
             // "in the last N days" rules count back from the session's clock
             lightcraft_catalog::rules::set_now(Some((self.clock)()));
@@ -595,8 +629,8 @@ impl Session {
             }
             if self.source == LibrarySource::Missing {
                 // only the photos the query kept (library photos, not Local browse records) are checked
-                let cat = &self.catalog;
-                visible.retain(|id| cmd::missing::is_missing(cat, *id));
+                let (cat, avail) = (&self.catalog, &self.media.availability);
+                visible.retain(|id| cmd::missing::is_missing(cat, avail, *id));
             }
             if self.source != LibrarySource::RecentlyDeleted {
                 visible = self.catalog.arrange_stacks(&visible);
@@ -693,6 +727,8 @@ mod tests_persist;
 #[cfg(test)]
 mod tests_prefs;
 #[cfg(test)]
+mod tests_segment;
+#[cfg(test)]
 mod tests_settings_files;
 #[cfg(test)]
 mod tests_spots;

crates/engine/src/library.rs

@@ -4,7 +4,7 @@
 //! ```text
 //! LightCraft Library/
 //!   catalog.snap   catalog.log      (lightcraft-catalog journal)
-//!   presets.json   view.json        (user presets + favourites; last source/filter/sort/selection)
+//!   presets.json   view.json        (user presets + favourites; last source/sort/selection)
 //!   prefs.json     (library preferences: XMP sidecars, import defaults, cache size, last export)
 //!   thumbs/        (rendered thumbnail cache, safe to delete)
 //!   Originals/     (photos imported with "copy into library")
@@ -102,7 +102,8 @@ struct PresetsFile {
 struct ViewFile {
     source: LibrarySource,
     browse: Option<crate::Browse>,
-    filter: lightcraft_catalog::Filter,
+    // No filter: a library opens unfiltered. A date, keyword or person left over from the last session
+    // would silently hide photos, with only a small badge to say so.
     sort: lightcraft_catalog::Sort,
     selection: Selection,
 }
@@ -346,7 +347,6 @@ impl Session {
         if let Some(v) = settings.read::<ViewFile>(files.as_mut(), "view.json") {
             self.source = v.source;
             self.browse = v.browse;
-            self.filter = v.filter;
             self.sort = v.sort;
             self.selection = v.selection;
             self.selection.ids.retain(|id| self.catalog.photo(*id).is_some());
@@ -494,17 +494,11 @@ impl Session {
     }
 
     fn view_json(&self) -> Vec<u8> {
-        let view = ViewFile {
-            source: self.source,
-            browse: self.browse.clone(),
-            filter: self.filter.clone(),
-            sort: self.sort,
-            selection: self.selection.clone(),
-        };
+        let view = ViewFile { source: self.source, browse: self.browse.clone(), sort: self.sort, selection: self.selection.clone() };
         serde_json::to_vec_pretty(&view).unwrap_or_default()
     }
 
-    /// Save the view state (source, filter, sort, selection) if it changed since it was last
+    /// Save the view state (source, sort, selection) if it changed since it was last
     /// written. Native hosts get this from [`Session::close_library`]; the browser host calls it
     /// periodically, since a tab can be closed without notice.
     pub fn save_view(&mut self) {

crates/engine/src/media.rs

@@ -26,7 +26,7 @@ use lightcraft_raster::{Histogram, Rgb32f, Rgba8};
 use serde::{Deserialize, Serialize};
 
 /// Bump when the pipeline's output changes, to invalidate cached thumbnails.
-pub const RENDER_CACHE_VERSION: u64 = 4;
+pub const RENDER_CACHE_VERSION: u64 = 11;
 
 /// Thumbnails render at one of these long edges (so window/cell size changes reuse the cache).
 pub const THUMB_SIZES: [usize; 4] = [128, 256, 384, 512];
@@ -71,9 +71,31 @@ pub type FileLoader = Arc<dyn Fn(&str, usize) -> Result<(Rgb32f, SourceInfo), St
 /// `max_edge` (set by the app). `None`: no usable preview.
 pub type PreviewLoader = Arc<dyn Fn(&str, usize) -> Option<Rgba8> + Send + Sync>;
 
+/// Pixels and the source interpretation learned while decoding; they must be cached together.
+#[derive(Clone)]
+pub struct DecodedSource {
+    pub image: Arc<Rgb32f>,
+    pub info: Option<SourceInfo>,
+    /// A smart preview's stored camera tone curve: the one decoder fact its pixels need that the
+    /// catalog's header facts lack (used when `info` is `None`).
+    pub camera_tone: Option<lightcraft_pipeline::tone::CameraTone>,
+}
+
+impl DecodedSource {
+    pub fn new(image: Arc<Rgb32f>, info: Option<SourceInfo>) -> Self {
+        DecodedSource { image, info, camera_tone: None }
+    }
+
+    /// What to render these pixels against: the decoder's facts, else `header` (the catalog's)
+    /// with any stored camera tone curve.
+    pub fn info_or(&self, header: SourceInfo) -> SourceInfo {
+        self.info.unwrap_or(SourceInfo { camera_tone: self.camera_tone.or(header.camera_tone), ..header })
+    }
+}
+
 #[derive(Clone)]
 pub enum SourceRef {
-    Loaded(Arc<Rgb32f>),
+    Loaded(Box<DecodedSource>),
     Demo {
         scene: Box<lightcraft_scenes::Scene>,
         max_edge: usize,
@@ -82,6 +104,9 @@ pub enum SourceRef {
         path: String,
         max_edge: usize,
         loader: Option<FileLoader>,
+        /// The photo's smart preview, used when the original can't be read (offline drive). The
+        /// UI thread never checks whether the original is there; the render worker finds out.
+        fallback: Option<std::path::PathBuf>,
     },
     /// A smart preview standing in for a missing original.
     Smart {
@@ -91,28 +116,41 @@ pub enum SourceRef {
 
 impl SourceRef {
     pub fn load(&self) -> Result<Arc<Rgb32f>, String> {
-        match self {
-            SourceRef::Loaded(a) => Ok(a.clone()),
-            SourceRef::Demo { scene, max_edge } => Ok(Arc::new(scene.render_fit(*max_edge))),
-            SourceRef::File { path, max_edge, loader } => match loader {
-                Some(l) => l(path, *max_edge).map(|(img, _)| Arc::new(img)),
-                None => Err(format!("no decoder available for {path}")),
-            },
+        self.load_source().map(|s| s.image)
+    }
+
+    pub fn load_source(&self) -> Result<DecodedSource, String> {
+        let image = match self {
+            SourceRef::Loaded(a) => return Ok((**a).clone()),
+            SourceRef::Demo { scene, max_edge } => Arc::new(scene.render_fit(*max_edge)),
+            SourceRef::File { path, max_edge, loader, fallback } => {
+                let r = match loader {
+                    Some(l) => l(path, *max_edge).map(|(image, info)| DecodedSource::new(Arc::new(image), Some(info))),
+                    None => Err(format!("no decoder available for {path}")),
+                };
+                // An offline original renders from its smart preview (no decoder facts: header ones).
+                return match (r, fallback) {
+                    #[cfg(not(target_arch = "wasm32"))]
+                    (Err(e), Some(sp)) if crate::smart::is_valid(sp) => crate::smart::load(sp).map_err(|e2| format!("{e}; smart preview: {e2}")),
+                    (r, _) => r,
+                };
+            }
             #[cfg(not(target_arch = "wasm32"))]
-            SourceRef::Smart { path } => crate::smart::load(path),
+            SourceRef::Smart { path } => return crate::smart::load(path),
             #[cfg(target_arch = "wasm32")]
-            SourceRef::Smart { .. } => Err("smart previews are not available here".into()),
-        }
+            SourceRef::Smart { .. } => return Err("smart previews are not available here".into()),
+        };
+        Ok(DecodedSource::new(image, None))
     }
 }
 
 pub struct MediaCache {
     /// Decoded thumbnail-level sources (LRU by bytes).
-    thumbs: Lru<PhotoId, Arc<Rgb32f>>,
+    thumbs: Lru<PhotoId, DecodedSource>,
     /// Decoded preview-level sources with their last use ([`lightcraft_preview::next_tick`]).
-    previews: Vec<(PhotoId, Arc<Rgb32f>, u64)>,
+    previews: Vec<(PhotoId, DecodedSource, u64)>,
     /// The last full-resolution original (exports; one at a time: ~300 MB at 24 MP).
-    full: Option<(PhotoId, Arc<Rgb32f>, u64)>,
+    full: Option<(PhotoId, DecodedSource, u64)>,
     /// How many previews to keep (LRU).
     pub preview_capacity: usize,
     /// Bytes all decoded sources and rendered previews in memory may take together (the cache
@@ -125,6 +163,9 @@ pub struct MediaCache {
     pub file_bytes: Option<crate::merge::ByteReader>,
     /// The library's smart previews folder (originals offline: render from the proxy).
     pub smart_dir: Option<std::path::PathBuf>,
+    /// Whether originals (and smart previews) are on disk: cached and checked off the UI thread
+    /// in the app (see [`crate::availability`]).
+    pub availability: crate::availability::Availability,
     scenes: Vec<lightcraft_scenes::Scene>,
     /// Rendered thumbnails (memory, plus disk once a library is attached).
     pub rendered: Arc<PreviewCache>,
@@ -144,6 +185,7 @@ impl Default for MediaCache {
             preview_loader: None,
             file_bytes: None,
             smart_dir: None,
+            availability: Default::default(),
             scenes: Vec::new(),
             rendered: Arc::new(PreviewCache::memory(rendered_budget(budget))),
         }
@@ -156,7 +198,7 @@ fn rendered_budget(share: usize) -> usize {
 }
 
 fn source_bytes(img: &Rgb32f) -> usize {
-    img.data.len() * 12 + 64
+    img.data.len() * 12 + 64 + std::mem::size_of::<SourceInfo>()
 }
 
 impl MediaCache {
@@ -207,8 +249,8 @@ impl MediaCache {
             let Some((tick, which)) = candidates.into_iter().flatten().min() else { break };
             let freed = match which {
                 0 => self.thumbs.pop_oldest(),
-                1 => self.previews.iter().position(|e| e.2 == tick).map(|i| source_bytes(&self.previews.remove(i).1)),
-                2 => self.full.take().map(|e| source_bytes(&e.1)),
+                1 => self.previews.iter().position(|e| e.2 == tick).map(|i| source_bytes(&self.previews.remove(i).1.image)),
+                2 => self.full.take().map(|e| source_bytes(&e.1.image)),
                 _ => self.rendered.evict_oldest(),
             };
             match freed {
@@ -219,6 +261,10 @@ impl MediaCache {
     }
 
     pub fn get(&mut self, id: PhotoId, level: SourceLevel) -> Option<Arc<Rgb32f>> {
+        self.get_source(id, level).map(|s| s.image)
+    }
+
+    fn get_source(&mut self, id: PhotoId, level: SourceLevel) -> Option<DecodedSource> {
         match level {
             SourceLevel::Thumb => self.thumbs.get(&id).cloned(),
             SourceLevel::Preview => self.previews.iter_mut().find(|e| e.0 == id).map(|e| {
@@ -232,11 +278,31 @@ impl MediaCache {
         }
     }
 
+    /// The facts of photo `id`'s cached sources: the decoder's when one has them, else `header`
+    /// (with a smart preview's stored camera tone curve).
+    fn source_facts(&self, id: PhotoId, header: SourceInfo) -> SourceInfo {
+        let cached = || {
+            self.thumbs
+                .peek(&id)
+                .into_iter()
+                .chain(self.previews.iter().filter(|e| e.0 == id).map(|e| &e.1))
+                .chain(self.full.iter().filter(|e| e.0 == id).map(|e| &e.1))
+        };
+        match cached().find(|s| s.info.is_some()).or_else(|| cached().next()) {
+            Some(s) => s.info_or(header),
+            None => header,
+        }
+    }
+
     pub fn insert(&mut self, id: PhotoId, level: SourceLevel, img: Arc<Rgb32f>) {
+        self.insert_source(id, level, DecodedSource::new(img, None));
+    }
+
+    fn insert_source(&mut self, id: PhotoId, level: SourceLevel, img: DecodedSource) {
         let tick = lightcraft_preview::next_tick();
         match level {
             SourceLevel::Thumb => {
-                let cost = source_bytes(&img);
+                let cost = source_bytes(&img.image);
                 self.thumbs.insert(id, img, cost);
             }
             SourceLevel::Preview => {
@@ -270,29 +336,36 @@ impl MediaCache {
     /// Decoded sources held: (thumbnail level, preview level, full size).
     pub fn usage(&self) -> (crate::memory::Usage, crate::memory::Usage, crate::memory::Usage) {
         use crate::memory::Usage;
-        let previews = Usage::new(self.previews.len(), self.previews.iter().map(|e| source_bytes(&e.1)).sum());
-        let full = self.full.as_ref().map(|e| Usage::new(1, source_bytes(&e.1))).unwrap_or_default();
+        let previews = Usage::new(self.previews.len(), self.previews.iter().map(|e| source_bytes(&e.1.image)).sum());
+        let full = self.full.as_ref().map(|e| Usage::new(1, source_bytes(&e.1.image))).unwrap_or_default();
         (Usage::new(self.thumbs.len(), self.thumbs.cost()), previews, full)
     }
 
     pub fn source_ref(&mut self, p: &Photo, level: SourceLevel) -> SourceRef {
-        if let Some(a) = self.get(p.id, level) {
-            return SourceRef::Loaded(a);
+        if let Some(a) = self.get_source(p.id, level) {
+            return SourceRef::Loaded(Box::new(a));
         }
         // Procedural scenes have a nominal size: "full" is that size, not unbounded.
         let max_edge = level.max_edge().min(match (&p.source, level) {
             (Source::Demo { .. }, SourceLevel::Full) => p.width.max(p.height).max(1) as usize,
             _ => usize::MAX,
         });
-        // the original is offline: its smart preview, when there is one
+        // the original is offline: its smart preview, when there is one. Only cached answers are
+        // used here (no file-system call on the UI thread in the app); an original not known to
+        // be offline is tried first and its smart preview is the render worker's fallback.
         #[cfg(not(target_arch = "wasm32"))]
-        if let (Source::File { path }, Some(dir)) = (&p.source, &self.smart_dir)
-            && !std::path::Path::new(path).exists()
-        {
+        if let (Source::File { path }, Some(dir)) = (&p.source, &self.smart_dir) {
             let sp = dir.join(crate::smart::file_name(p));
-            if crate::smart::is_valid(&sp) {
+            // (a proxy cut short fails to load, like the offline original; the worker's fallback
+            // in `SourceRef::load` only uses a proxy that passes `smart::is_valid`)
+            if self.availability.is_offline(path) && self.availability.exists(&sp.to_string_lossy()) == Some(true) {
                 return SourceRef::Smart { path: sp };
             }
+            let mut r = self.origin_ref(&p.source, max_edge);
+            if let SourceRef::File { fallback, .. } = &mut r {
+                *fallback = Some(sp);
+            }
+            return r;
         }
         self.origin_ref(&p.source, max_edge)
     }
@@ -307,10 +380,10 @@ impl MediaCache {
                 }
                 match self.scenes.iter().find(|s| s.id == *scene) {
                     Some(s) => SourceRef::Demo { scene: Box::new(s.clone()), max_edge },
-                    None => SourceRef::File { path: format!("demo:{scene}"), max_edge, loader: None },
+                    None => SourceRef::File { path: format!("demo:{scene}"), max_edge, loader: None, fallback: None },
                 }
             }
-            Source::File { path } => SourceRef::File { path: path.clone(), max_edge, loader: self.file_loader.clone() },
+            Source::File { path } => SourceRef::File { path: path.clone(), max_edge, loader: self.file_loader.clone(), fallback: None },
         }
     }
 }
@@ -344,7 +417,7 @@ pub struct RenderResult {
     pub key: u64,
     pub rendered: Result<Rendered, String>,
     /// A source that was loaded by this job (to be inserted into the cache).
-    pub loaded: Option<Arc<Rgb32f>>,
+    pub loaded: Option<DecodedSource>,
     /// Set for a [`QuickJob`]'s stand-in: where the image came from.
     pub quick: Option<QuickSource>,
 }
@@ -410,12 +483,14 @@ impl RenderJob {
             };
         }
         let was_loaded = matches!(self.source, SourceRef::Loaded(_));
-        match self.source.load() {
-            Ok(src) => {
+        match self.source.load_source() {
+            Ok(source) => {
+                let src = &source.image;
+                let info = source.info_or(self.info);
                 // Thumbnails (many small jobs side by side) stay on the CPU; views and exports use
                 // the GPU when there is one.
                 let gpu = self.cache.is_none();
-                let rendered = develop(&src, &self.info, &self.settings, &self.request, self.stages.as_deref(), gpu);
+                let rendered = develop(src, &info, &self.settings, &self.request, self.stages.as_deref(), gpu);
                 if let Some((cache, key)) = &self.cache {
                     cache.put(*key, Arc::new(rendered.image.clone()));
                 }
@@ -429,7 +504,7 @@ impl RenderJob {
                     level: self.level,
                     key: self.key,
                     rendered: Ok(rendered),
-                    loaded: (!was_loaded).then_some(src),
+                    loaded: (!was_loaded).then_some(source),
                     quick: None,
                 }
             }
@@ -521,11 +596,16 @@ pub fn content_key(p: &Photo) -> String {
 pub fn source_info(p: &Photo) -> SourceInfo {
     // Procedural demo scenes are scene-referred HDR (like raw files): use the filmic tone map.
     if matches!(p.source, Source::Demo { .. }) {
-        return SourceInfo { raw: true, as_shot_temp: 6500.0, as_shot_tint: 0.0, lens: None };
+        return SourceInfo { raw: true, ..Default::default() };
     }
     // A raw shown from its embedded preview is a rendered (display-referred) JPEG: relative white
     // balance and the display tone curve, like any other rendered file.
-    if p.develops_raw() { SourceInfo { raw: true, as_shot_temp: 5500.0, as_shot_tint: 0.0, lens: p.embedded_lens } } else { SourceInfo::default() }
+    if p.develops_raw() {
+        let (temp, tint) = if p.relative_wb() { (6500.0, 0.0) } else { p.as_shot_wb.unwrap_or((5500.0, 0.0)) };
+        SourceInfo { raw: true, as_shot_temp: temp, as_shot_tint: tint, lens: p.embedded_lens, relative_wb: p.relative_wb(), ..Default::default() }
+    } else {
+        SourceInfo::default()
+    }
 }
 
 impl crate::Session {
@@ -567,7 +647,13 @@ impl crate::Session {
             ^ id.0.wrapping_mul(0x9e37_79b9_7f4a_7c15)
             ^ content.rotate_left(17);
         let cache = thumb_bucket.map(|b| {
-            let k = Hasher128::new().str(&content_key(&p)).u64(settings.hash64()).u64(b as u64).u64(RENDER_CACHE_VERSION).finish();
+            let k = Hasher128::new()
+                .str(&content_key(&p))
+                .u64(settings.hash64())
+                .u64(b as u64)
+                .u64(RENDER_CACHE_VERSION)
+                .u64(crate::camera_profiles::cache_key())
+                .finish();
             (self.media.rendered.clone(), k)
         });
         Some(RenderJob {
@@ -596,7 +682,14 @@ impl crate::Session {
 
     /// Cache key of a variant thumbnail ([`Self::variant_job`]).
     pub fn variant_key(p: &Photo, settings: &DevelopSettings, edge: usize) -> Hash128 {
-        Hasher128::new().str(&content_key(p)).str("variant").u64(settings.hash64()).u64(edge as u64).u64(RENDER_CACHE_VERSION).finish()
+        Hasher128::new()
+            .str(&content_key(p))
+            .str("variant")
+            .u64(settings.hash64())
+            .u64(edge as u64)
+            .u64(RENDER_CACHE_VERSION)
+            .u64(crate::camera_profiles::cache_key())
+            .finish()
     }
 
     /// A thumbnail of `id` rendered with `settings` instead of its own (profile and preset
@@ -625,9 +718,58 @@ impl crate::Session {
         })
     }
 
+    /// A square close-up of `face` (normalized, in the photo's upright frame) for a People card: the
+    /// photo's own look with its crop replaced by a square around the face (room for hair and chin),
+    /// `edge` pixels across (≤ 512). The source level is the smallest that keeps the face sharp, up
+    /// to the preview. Cached like [`Self::variant_job`], and `key` likewise follows the content.
+    pub fn face_job(&mut self, id: PhotoId, face: lightcraft_geom::Rect, edge: usize) -> Option<RenderJob> {
+        let p = self.catalog.photo(id)?.clone();
+        // `face` is on the upright (EXIF-oriented) photo; the crop below is in the frame after the
+        // user's Rotate Left/Right, so carry the box (and the photo's size) over to it.
+        let orient = p.develop.orientation;
+        let face = orient.map_norm_rect(face);
+        let (w, h) = (f64::from(p.width.max(1)), f64::from(p.height.max(1)));
+        let (w, h) = if orient.swaps_axes() { (h, w) } else { (w, h) };
+        let side = ((face.x1 - face.x0) * w).max((face.y1 - face.y0) * h) * 1.7;
+        // finite, within the photo, and never wider than its short side (so the clamps below are valid)
+        let side = if side.is_finite() { side.clamp(1.0, w.min(h)) } else { w.min(h) };
+        let (cx, cy) = ((face.x0 + face.x1) / 2.0 * w, (face.y0 + face.y1) / 2.0 * h);
+        let (cx, cy) = (if cx.is_finite() { cx } else { w / 2.0 }, if cy.is_finite() { cy } else { h / 2.0 });
+        let (x0, y0) = (cx.clamp(side / 2.0, w - side / 2.0) - side / 2.0, cy.clamp(side / 2.0, h - side / 2.0) - side / 2.0);
+        let rect = lightcraft_geom::Rect { x0: x0 / w, y0: y0 / h, x1: (x0 + side) / w, y1: (y0 + side) / h };
+        let mut settings = (*p.develop).clone();
+        settings.crop = lightcraft_develop::Crop { geometry: lightcraft_geom::CropGeometry { rect, angle: 0.0 }, ..Default::default() };
+        let edge = edge.clamp(16, SourceLevel::Thumb.max_edge());
+        // pixels along the long edge that leave `edge` across the crop
+        let needed = (edge as f64 * w.max(h) / side).ceil().min(SourceLevel::Preview.max_edge() as f64);
+        let level = SourceLevel::for_size(needed as usize);
+        let source = self.media.source_ref(&p, level);
+        let ck = Self::variant_key(&p, &settings, edge);
+        Some(RenderJob {
+            photo: id,
+            level,
+            source,
+            origin: p.source.clone(),
+            info: source_info(&p),
+            settings: Arc::new(settings),
+            request: RenderRequest { apply_crop: true, ..RenderRequest::fit(edge, edge) },
+            key: (ck.0 as u64) ^ ((ck.0 >> 64) as u64),
+            cache: Some((self.media.rendered.clone(), ck)),
+            stages: None,
+            view_cache: None,
+        })
+    }
+
     /// Size-independent cache key of a photo's view render (loupe) for its current settings.
     fn view_key(p: &Photo, apply_crop: bool) -> Hash128 {
-        Hasher128::new().str(&content_key(p)).str("view").u64(p.develop.hash64()).u64(apply_crop as u64).u64(RENDER_CACHE_VERSION).finish()
+        Hasher128::new()
+            .str(&content_key(p))
+            .str("view")
+            .u64(p.develop.hash64())
+            .u64(apply_crop as u64)
+            .u64(RENDER_CACHE_VERSION)
+            .u64(crate::camera_profiles::cache_key())
+            .finish()
     }
 
     /// The loupe's render job: like [`Self::render_job`], and a full-quality result is kept as the
@@ -680,7 +822,7 @@ impl crate::Session {
     /// Accept a finished job's loaded source into the cache.
     pub fn accept(&mut self, r: &RenderResult) {
         if let Some(src) = &r.loaded {
-            self.media.insert(r.photo, r.level, src.clone());
+            self.media.insert_source(r.photo, r.level, src.clone());
         }
     }
 
@@ -723,12 +865,19 @@ impl crate::Session {
         Ok(job)
     }
 
+    /// Prefer decoder facts to header-only metadata for pixel-statistics commands.
+    pub fn source_info(&self, id: PhotoId) -> SourceInfo {
+        let header = self.catalog.photo(id).map(|p| source_info(p)).unwrap_or_default();
+        self.media.source_facts(id, header)
+    }
+
     /// The source proxy for pixel-statistics commands (auto tone/WB), loading synchronously.
     pub fn source_now(&mut self, id: PhotoId, level: SourceLevel) -> Result<Arc<Rgb32f>, String> {
         let p = self.catalog.photo(id).ok_or("no such photo")?.clone();
-        let r = self.media.source_ref(&p, level).load()?;
-        self.media.insert(id, level, r.clone());
-        Ok(r)
+        let r = self.media.source_ref(&p, level).load_source()?;
+        let image = r.image.clone();
+        self.media.insert_source(id, level, r);
+        Ok(image)
     }
 }
 
@@ -743,7 +892,9 @@ pub struct ProbeInfo {
     pub captured: Option<String>,
     pub meta: lightcraft_catalog::Meta,
     pub as_shot_wb: Option<(f64, f64)>,
-    /// Hash of the file's bytes (hex), for duplicate detection.
+    /// Hash of the file's bytes (hex), for duplicate detection. When it is a 32-digit
+    /// [`lightcraft_preview::hash_bytes`] of the whole file (as the native probe computes it),
+    /// Import → Copy verifies each copy against it instead of reading the source again.
     pub content_hash: Option<String>,
     /// Lens corrections embedded in the file (DNG opcodes).
     pub embedded_lens: Option<lightcraft_develop::EmbeddedLens>,
@@ -760,6 +911,42 @@ pub type FileProbe = Arc<dyn Fn(&str) -> Result<ProbeInfo, String> + Send + Sync
 mod tests {
     use super::*;
 
+    #[test]
+    fn decoder_info_survives_render_jobs_cache_and_eviction() {
+        let tone = lightcraft_pipeline::tone::CameraTone::new(std::array::from_fn(|i| {
+            let x = 0.01 * (i + 1) as f32;
+            [x, (x * 2.0).min(0.9)]
+        }))
+        .unwrap();
+        let info = SourceInfo { raw: true, relative_wb: true, camera_tone: Some(tone), ..Default::default() };
+        let mut s = crate::Session::with_demo();
+        let id = s.active().unwrap();
+        let mut job = s.render_job(id, 64, 64, false, true).unwrap();
+        job.source = SourceRef::File {
+            path: "synthetic.arw".into(),
+            max_edge: 64,
+            loader: Some(Arc::new(move |_, _| {
+                let mut image = Rgb32f::new(64, 64);
+                image.data.fill([0.1; 3]);
+                Ok((image, info))
+            })),
+            fallback: None,
+        };
+        job.info = SourceInfo::default(); // Header facts cannot override decoder facts.
+        job.settings = Arc::new(DevelopSettings::default());
+        let r = job.clone().run();
+        assert_eq!(r.loaded.as_ref().unwrap().info, Some(info));
+        let expected = lightcraft_pipeline::render(&r.loaded.as_ref().unwrap().image, &info, &job.settings, &job.request);
+        assert_eq!(r.rendered.as_ref().unwrap().image.data, expected.image.data);
+        s.accept(&r);
+        job.source = s.media.source_ref(s.catalog.photo(id).unwrap(), job.level);
+        let again = job.run();
+        assert!(again.loaded.is_none());
+        assert_eq!(r.rendered.unwrap().image.data, again.rendered.unwrap().image.data);
+        s.media.forget(id);
+        assert!(s.media.get_source(id, r.level).is_none());
+    }
+
     #[test]
     fn budget_evicts_least_recently_used_across_caches() {
         let img = |w: usize| Arc::new(Rgb32f::new(w, w));

crates/engine/src/originals.rs

@@ -15,6 +15,8 @@ use lightcraft_catalog::{Catalog, Source};
 pub struct OriginalGuard {
     /// lower-case file name → (path on disk, what it is: "the original of IMG_1.CR3", …)
     by_name: HashMap<String, Vec<(PathBuf, String)>>,
+    /// The entries of `by_name` that are symlinks, found on the first check that needs them.
+    links: std::sync::OnceLock<Vec<(PathBuf, String)>>,
 }
 
 impl OriginalGuard {
@@ -32,6 +34,7 @@ impl OriginalGuard {
     /// Protect `path` (an original named `label`) and its sidecars (`IMG_1.xmp`, `IMG_1.CR3.xmp`).
     pub fn add(&mut self, path: &Path, label: &str) {
         let Some(name) = path.file_name().map(|n| n.to_string_lossy().to_string()) else { return };
+        self.links = std::sync::OnceLock::new();
         let mut put = |file: String, p: PathBuf, what: String| self.by_name.entry(file.to_lowercase()).or_default().push((p, what));
         put(name.clone(), path.to_path_buf(), format!("the original of {label}"));
         let stem = path.file_stem().map(|s| s.to_string_lossy().to_string()).unwrap_or_default();
@@ -58,6 +61,19 @@ impl OriginalGuard {
                 }
             }
         }
+        // An imported symlink can have a different name from its original. A write to
+        // that original would change what the library reads through the link. Only do
+        // this fallback for existing targets that the name index did not protect; the links are
+        // looked up once per guard, not once per target.
+        let links = self.links.get_or_init(|| self.by_name.values().flatten().filter(|(p, _)| std::fs::read_link(p).is_ok()).cloned().collect());
+        for (p, what) in links {
+            if same_file(p, target) {
+                return Err(format!(
+                    "{} is {what} in the library: LightCraft never writes over an original (choose another folder or file name)",
+                    target.display()
+                ));
+            }
+        }
         Ok(())
     }
 }
@@ -68,9 +84,14 @@ impl crate::Session {
         OriginalGuard::new(&self.catalog)
     }
 
-    /// `Err` when writing `path` would replace a catalogued photo's original or sidecar.
+    /// `Err` when writing `path` would replace a catalogued photo's original or sidecar. A free
+    /// path (the usual case) is answered without building the guard over the whole library.
     pub fn check_write_target(&self, path: &str) -> Result<(), String> {
-        self.original_guard().check(Path::new(path))
+        let path = Path::new(path);
+        if std::fs::symlink_metadata(path).is_err() {
+            return Ok(()); // nothing there to replace
+        }
+        self.original_guard().check(path)
     }
 }
 

crates/engine/src/rename.rs

@@ -538,6 +538,92 @@ fn set_file_ops_to(op: &Op, to: &HashSet<&str>, out: &mut Vec<Op>) {
     }
 }
 
+/// The photos among `ids` a rename handles, in order: photos sharing one file (virtual copies)
+/// rename once. No file-system calls.
+pub fn rename_photos(cat: &lightcraft_catalog::Catalog, ids: &[PhotoId]) -> Vec<std::sync::Arc<Photo>> {
+    let mut seen_paths: HashSet<String> = HashSet::new();
+    ids.iter()
+        .filter_map(|id| cat.photo(*id))
+        .filter(|p| match &p.source {
+            Source::File { path } => seen_paths.insert(path.clone()),
+            _ => true,
+        })
+        .cloned()
+        .collect()
+}
+
+/// [`Session::plan_rename`] for [`rename_photos`], with the "is this name taken on disk?" check
+/// supplied: the Rename dialog plans its preview on a worker thread (a check can block on a slow
+/// drive). Whether a case-only change names this very file is decided on the disk.
+pub fn plan_rename_photos(photos: &[std::sync::Arc<Photo>], template: &str, start: usize, exists: &dyn Fn(&str) -> bool) -> Vec<RenamePlan> {
+    plan_rename_core(photos, template, start, &|p| exists(&p.to_string_lossy()), &|a, b| RealFs.same_file(a, b))
+}
+
+/// Plan renaming `photos`: `exists` says whether something answers to a path, `same_file` whether
+/// two spellings name one file (see [`MoveFs`]).
+fn plan_rename_core(
+    photos: &[std::sync::Arc<Photo>],
+    template: &str,
+    start: usize,
+    exists: &dyn Fn(&Path) -> bool,
+    same_file: &dyn Fn(&Path, &Path) -> bool,
+) -> Vec<RenamePlan> {
+    let mut taken: HashSet<String> = HashSet::new(); // lower-case target paths/names claimed in this batch
+    let mut out = Vec::new();
+    for (seq, p) in (start..).zip(photos) {
+        let want = expand(template, p, seq);
+        let (stem, ext) = split_ext(&want);
+        let (stem, ext) = (stem.to_string(), ext.to_string());
+        let candidate = |k: usize| {
+            if k == 0 {
+                want.clone()
+            } else if ext.is_empty() {
+                format!("{stem}-{k}")
+            } else {
+                format!("{stem}-{k}.{ext}")
+            }
+        };
+        let (to, to_path) = match &p.source {
+            Source::File { path } => {
+                let dir = Path::new(path).parent().map(Path::to_path_buf).unwrap_or_default();
+                let mut k = 0;
+                loop {
+                    let name = candidate(k);
+                    let tp = dir.join(&name).to_string_lossy().to_string();
+                    let key = tp.to_lowercase();
+                    // this very file, maybe spelled differently (case-insensitive volume)? By
+                    // identity: on a case-sensitive volume `img_1.jpg` may be another photo
+                    let (from, to) = (Path::new(path), Path::new(&tp));
+                    let same = tp == *path || (from != to && key == path.to_lowercase() && exists(to) && same_file(from, to));
+                    // free: not claimed in this batch and not on disk (unless it is this very file).
+                    // A file this batch moves away still counts as taken: simple and safe.
+                    if !taken.contains(&key) && (same || !exists(to)) {
+                        taken.insert(key);
+                        break (name, Some(tp));
+                    }
+                    k += 1;
+                }
+            }
+            Source::Demo { .. } => {
+                let mut k = 0;
+                loop {
+                    let name = candidate(k);
+                    if taken.insert(format!("demo:{}", name.to_lowercase())) {
+                        break (name, None);
+                    }
+                    k += 1;
+                }
+            }
+        };
+        let from_path = match &p.source {
+            Source::File { path } => Some(path.clone()),
+            _ => None,
+        };
+        out.push(RenamePlan { id: p.id.0, from: p.file_name.clone(), to, from_path, to_path });
+    }
+    out
+}
+
 impl Session {
     /// Plan renaming `ids` with `template` (sequence numbers from `start`), resolving collisions.
     pub fn plan_rename(&self, ids: &[PhotoId], template: &str, start: usize) -> Vec<RenamePlan> {
@@ -546,70 +632,7 @@ impl Session {
 
     /// [`Session::plan_rename`] on the file system `fs`.
     pub(crate) fn plan_rename_with(&self, fs: &dyn MoveFs, ids: &[PhotoId], template: &str, start: usize) -> Vec<RenamePlan> {
-        // photos sharing one file (virtual copies) rename once
-        let mut seen_paths: HashSet<String> = HashSet::new();
-        let mut taken: HashSet<String> = HashSet::new(); // lower-case target paths/names claimed in this batch
-        let mut out = Vec::new();
-        let mut seq = start;
-        for id in ids {
-            let Some(p) = self.catalog.photo(*id) else { continue };
-            if let Source::File { path } = &p.source
-                && !seen_paths.insert(path.clone())
-            {
-                continue;
-            }
-            let want = expand(template, p, seq);
-            seq += 1;
-            let (stem, ext) = split_ext(&want);
-            let (stem, ext) = (stem.to_string(), ext.to_string());
-            let candidate = |k: usize| {
-                if k == 0 {
-                    want.clone()
-                } else if ext.is_empty() {
-                    format!("{stem}-{k}")
-                } else {
-                    format!("{stem}-{k}.{ext}")
-                }
-            };
-            let (to, to_path) = match &p.source {
-                Source::File { path } => {
-                    let dir = Path::new(path).parent().map(Path::to_path_buf).unwrap_or_default();
-                    let mut k = 0;
-                    loop {
-                        let name = candidate(k);
-                        let tp = dir.join(&name).to_string_lossy().to_string();
-                        let key = tp.to_lowercase();
-                        // this very file, maybe spelled differently (case-insensitive volume)? By
-                        // identity: on a case-sensitive volume `img_1.jpg` may be another photo
-                        let same = tp == *path || is_respelling(fs, Path::new(path), Path::new(&tp));
-                        // free: not claimed in this batch and not on disk (unless it is this very file).
-                        // A file this batch moves away still counts as taken: simple and safe.
-                        let on_disk = fs.exists(Path::new(&tp)) && !same;
-                        if !taken.contains(&key) && !on_disk {
-                            taken.insert(key);
-                            break (name, Some(tp));
-                        }
-                        k += 1;
-                    }
-                }
-                Source::Demo { .. } => {
-                    let mut k = 0;
-                    loop {
-                        let name = candidate(k);
-                        if taken.insert(format!("demo:{}", name.to_lowercase())) {
-                            break (name, None);
-                        }
-                        k += 1;
-                    }
-                }
-            };
-            let from_path = match &p.source {
-                Source::File { path } => Some(path.clone()),
-                _ => None,
-            };
-            out.push(RenamePlan { id: id.0, from: p.file_name.clone(), to, from_path, to_path });
-        }
-        out
+        plan_rename_core(&rename_photos(&self.catalog, ids), template, start, &|p| fs.exists(p), &|a, b| fs.same_file(a, b))
     }
 
     /// Carry out `plans`: move the files (rolled back on failure), then commit one undoable op

crates/engine/src/segment/download.rs

@@ -0,0 +1,146 @@
+//! The model download as a background task the session starts, watches and cancels without
+//! ever blocking: progress lives in atomics, messages behind a mutex only ever `try_lock`ed
+//! by the session (the download thread holds it for a few instructions at a time).
+
+use std::path::PathBuf;
+use std::sync::atomic::{AtomicBool, AtomicU64, Ordering};
+use std::sync::{Arc, Mutex};
+
+use lightcraft_segment::fetch::{self, Options, Progress};
+
+/// What the session sees of a download.
+#[derive(Clone, Debug, Default, PartialEq, Eq, serde::Serialize)]
+pub struct Status {
+    pub running: bool,
+    pub done: u64,
+    pub total: u64,
+    /// The file being fetched.
+    pub file: String,
+    /// The last download's error (cleared when a new one starts).
+    pub error: Option<String>,
+    /// The last download finished and the files are in place.
+    pub finished: bool,
+}
+
+#[derive(Default)]
+struct Text {
+    file: String,
+    error: Option<String>,
+}
+
+#[derive(Default)]
+struct Shared {
+    running: AtomicBool,
+    cancel: AtomicBool,
+    finished: AtomicBool,
+    done: AtomicU64,
+    total: AtomicU64,
+    text: Mutex<Text>,
+}
+
+/// Clears `running` when the download thread ends, however it ends.
+struct Running(Arc<Shared>);
+
+impl Drop for Running {
+    fn drop(&mut self) {
+        self.0.running.store(false, Ordering::SeqCst);
+    }
+}
+
+#[derive(Default)]
+pub struct Downloader {
+    shared: Arc<Shared>,
+    /// The last text seen (when the download thread held the lock at that moment).
+    last: Mutex<Text>,
+}
+
+fn lock(m: &Mutex<Text>) -> std::sync::MutexGuard<'_, Text> {
+    m.lock().unwrap_or_else(std::sync::PoisonError::into_inner)
+}
+
+impl Downloader {
+    pub fn status(&self) -> Status {
+        let s = &self.shared;
+        if let Ok(t) = s.text.try_lock()
+            && let Ok(mut last) = self.last.try_lock()
+        {
+            last.file.clone_from(&t.file);
+            last.error.clone_from(&t.error);
+        }
+        // (only the session's thread locks `last`)
+        let (file, error) = self.last.try_lock().map(|l| (l.file.clone(), l.error.clone())).unwrap_or_default();
+        Status {
+            running: s.running.load(Ordering::SeqCst),
+            done: s.done.load(Ordering::SeqCst),
+            total: s.total.load(Ordering::SeqCst),
+            file,
+            error,
+            finished: s.finished.load(Ordering::SeqCst),
+        }
+    }
+
+    pub fn running(&self) -> bool {
+        self.shared.running.load(Ordering::SeqCst)
+    }
+
+    /// Ask a running download to stop (it keeps its partial files to resume later).
+    pub fn cancel(&self) -> bool {
+        let running = self.running();
+        if running {
+            self.shared.cancel.store(true, Ordering::SeqCst);
+        }
+        running
+    }
+
+    /// Start downloading `files` from `mirrors` into `dir` on a background thread. False when
+    /// one is already running.
+    pub fn start(&self, files: &'static [fetch::FileSpec], mirrors: Vec<String>, dir: PathBuf, opts: Options) -> Result<bool, String> {
+        let s = self.shared.clone();
+        if s.running.swap(true, Ordering::SeqCst) {
+            return Ok(false);
+        }
+        s.cancel.store(false, Ordering::SeqCst);
+        s.finished.store(false, Ordering::SeqCst);
+        s.done.store(0, Ordering::SeqCst);
+        s.total.store(files.iter().filter_map(|f| f.size).sum(), Ordering::SeqCst);
+        // nothing else runs while `running` was false
+        *lock(&s.text) = Text::default();
+        *lock(&self.last) = Text::default();
+        let guard = Running(s.clone());
+        let spawned = std::thread::Builder::new().name("sam3-download".into()).spawn(move || {
+            let s = guard.0.clone();
+            let mut last_file = String::new();
+            let mut on_progress = |p: &Progress| {
+                s.done.store(p.done, Ordering::SeqCst);
+                s.total.store(p.total, Ordering::SeqCst);
+                if p.file != last_file {
+                    last_file.clone_from(&p.file);
+                    lock(&s.text).file.clone_from(&p.file);
+                }
+            };
+            let r =
+                std::panic::catch_unwind(std::panic::AssertUnwindSafe(|| fetch::download(files, &mirrors, &dir, &opts, &s.cancel, &mut on_progress)));
+            let error = match r {
+                Ok(Ok(())) => {
+                    s.finished.store(true, Ordering::SeqCst);
+                    log::info!("SAM 3 model downloaded to {}", dir.display());
+                    None
+                }
+                Ok(Err(e)) => Some(e.to_string()),
+                Err(_) => Some("the download failed unexpectedly".to_string()),
+            };
+            if let Some(e) = &error {
+                log::warn!("SAM 3 download: {e}");
+            }
+            lock(&s.text).error = error;
+            drop(guard);
+        });
+        match spawned {
+            Ok(_) => Ok(true),
+            Err(e) => {
+                // the closure (and its guard) was dropped: `running` is false again
+                Err(format!("could not start the download: {e}"))
+            }
+        }
+    }
+}

crates/engine/src/segment/mod.rs

@@ -0,0 +1,715 @@
+//! AI masks: Object (clicks) and Describe (text) selections computed with SAM 3
+//! (`lightcraft-segment`, cargo feature `sam`; the desktop app enables it).
+//!
+//! **Nothing requires the model.** It is not part of LightCraft (SAM License); the user
+//! downloads it when they first use an AI mask and agree to (`segment.model.download`), or
+//! puts the files in the model folder themselves. Without it, AI mask requests fail with a
+//! clear "not installed" error; renders, exports and every other feature never touch it
+//! (stored segmentations are plain data in the develop settings).
+//!
+//! The model sees the photo as developed, uncropped and without masks, at 1008 px — the frame
+//! mask coordinates live in — so a stored segmentation lines up with the photo at any size.
+//! Everything that touches the model (loading it, rendering and encoding the photo, clicks,
+//! descriptions, detail passes) runs on one worker thread ([`worker`]); the session talks to it
+//! over channels and never waits on a lock. With [`Segmenter::background`] (the desktop app)
+//! commands return at once and [`Session::segment_poll`] applies the results; without it (CLI,
+//! MCP, tests) they wait for the worker.
+
+#[cfg(feature = "sam")]
+mod download;
+#[cfg(feature = "sam")]
+mod worker;
+
+use std::path::PathBuf;
+
+use lightcraft_catalog::PhotoId;
+use lightcraft_develop::{MaskShape, SegMask};
+use lightcraft_geom::Point;
+
+use crate::Session;
+
+/// Long edge of the image the model sees.
+pub const INPUT_EDGE: usize = 1008;
+/// Download size of the model (`model.safetensors`; the tokenizer files add ~2 MB).
+pub const MODEL_BYTES: u64 = 3_439_938_512;
+/// The model's licence (not LightCraft's): shown before downloading.
+pub const LICENSE_NAME: &str = "SAM License (Meta)";
+pub const LICENSE_URL: &str = "https://github.com/facebookresearch/sam3/blob/main/LICENSE";
+/// How errors about a missing model start (the UI offers the download on it).
+pub const NOT_INSTALLED: &str = "The SAM 3 model is not installed";
+/// Longest a waiting command (CLI, MCP) waits for the model (loading on a CPU can take minutes).
+#[cfg_attr(not(feature = "sam"), allow(dead_code))]
+const WAIT: std::time::Duration = std::time::Duration::from_secs(15 * 60);
+/// Most clicks one Object selection takes (the model's prompt grows with each).
+pub const MAX_CLICKS: usize = 64;
+
+/// One click of an Object selection (normalized image coordinates).
+#[derive(Clone, Copy, Debug, PartialEq)]
+pub struct Click {
+    pub at: Point,
+    pub include: bool,
+}
+
+/// What a request's result is for (how [`Session::segment_poll`] applies it).
+#[derive(Clone, Debug, PartialEq)]
+#[cfg_attr(not(feature = "sam"), allow(dead_code))]
+pub(crate) enum Tag {
+    /// A command waiting for the result itself.
+    Wait,
+    /// Load the model and encode the photo ahead of the first click.
+    Prepare,
+    /// Object clicks on component `comp` of mask `mask`.
+    Clicks { photo: PhotoId, mask: u32, comp: usize, hint: Vec<Point>, exclude: Vec<Point> },
+    /// A Describe selection: a new mask (`mask: None`) or a component combined by `op`.
+    NewPrompt { photo: PhotoId, mask: Option<u32>, op: String, name: Option<String>, text: String },
+    /// A zoomed-in pass for a component, computed from `shape` (without its detail).
+    Detail { photo: PhotoId, mask: u32, comp: usize, shape: MaskShape },
+}
+
+/// The model input: 8-bit RGB.
+#[cfg_attr(not(feature = "sam"), allow(dead_code))]
+pub(crate) struct Input {
+    rgb: Vec<u8>,
+    w: usize,
+    h: usize,
+}
+
+/// What a detail pass re-runs.
+#[cfg_attr(not(feature = "sam"), allow(dead_code))]
+pub(crate) enum Prompt {
+    Clicks(Vec<Click>),
+    Text(String),
+}
+
+/// Object clicks sent to the worker and not applied yet (background mode): further clicks add
+/// to these, and the loupe shows them.
+#[derive(Clone, Debug, PartialEq)]
+pub struct PendingClicks {
+    pub photo: PhotoId,
+    pub mask: u32,
+    pub comp: usize,
+    pub hint: Vec<Point>,
+    pub exclude: Vec<Point>,
+}
+
+/// What [`Session::segment_poll`] did.
+#[derive(Debug, Default)]
+pub struct Polled {
+    /// A mask changed.
+    pub changed: bool,
+    /// Errors and notices from background work, for the user.
+    pub messages: Vec<String>,
+    /// A mask that got a new selection (worth a detail pass).
+    pub refine: Option<u32>,
+}
+
+/// The model download (`segment.model.*`).
+#[derive(Clone, Debug, Default, PartialEq, Eq, serde::Serialize)]
+pub struct DownloadStatus {
+    pub running: bool,
+    pub done: u64,
+    pub total: u64,
+    pub file: String,
+    pub error: Option<String>,
+    pub finished: bool,
+}
+
+/// The model (on its worker thread), the download, and AI mask requests in flight.
+pub struct Segmenter {
+    /// Where the `facebook/sam3` files live (set by the app; `None`: no AI masks).
+    pub dir: Option<PathBuf>,
+    /// The user's list of download mirrors (one base URL per line), if any.
+    pub mirrors_file: Option<PathBuf>,
+    /// Run requests in the background and apply them in [`Session::segment_poll`] (the
+    /// desktop app); otherwise commands wait for their result (CLI, MCP, tests).
+    pub background: bool,
+    pending: Option<PendingClicks>,
+    messages: Vec<String>,
+    #[cfg(feature = "sam")]
+    worker: worker::Worker,
+    #[cfg(feature = "sam")]
+    download: download::Downloader,
+    #[cfg(feature = "sam")]
+    results: (std::sync::mpsc::Sender<worker::Outcome>, std::sync::mpsc::Receiver<worker::Outcome>),
+}
+
+// (derivable only without the `sam` feature: the results channel has no Default)
+#[allow(clippy::derivable_impls)]
+impl Default for Segmenter {
+    fn default() -> Self {
+        Segmenter {
+            dir: None,
+            mirrors_file: None,
+            background: false,
+            pending: None,
+            messages: Vec::new(),
+            #[cfg(feature = "sam")]
+            worker: worker::Worker::default(),
+            #[cfg(feature = "sam")]
+            download: download::Downloader::default(),
+            #[cfg(feature = "sam")]
+            results: std::sync::mpsc::channel(),
+        }
+    }
+}
+
+impl Segmenter {
+    /// Whether this build can compute AI masks at all.
+    pub const AVAILABLE: bool = cfg!(feature = "sam");
+
+    /// Whether the model's files are in place.
+    pub fn installed(&self) -> bool {
+        #[cfg(feature = "sam")]
+        if let Some(dir) = &self.dir {
+            return lightcraft_segment::is_model_dir(dir);
+        }
+        false
+    }
+
+    /// Whether requests are queued or running (loading, analyzing the photo, a click…).
+    pub fn busy(&self) -> bool {
+        #[cfg(feature = "sam")]
+        return self.worker.pending() > 0;
+        #[cfg(not(feature = "sam"))]
+        false
+    }
+
+    /// Whether the slow part runs now: loading the model or analyzing a photo.
+    pub fn analyzing(&self) -> bool {
+        #[cfg(feature = "sam")]
+        return self.worker.encoding();
+        #[cfg(not(feature = "sam"))]
+        false
+    }
+
+    /// Whether a zoomed-in detail pass is queued or running.
+    pub fn detail_busy(&self) -> bool {
+        #[cfg(feature = "sam")]
+        return self.worker.detail() > 0;
+        #[cfg(not(feature = "sam"))]
+        false
+    }
+
+    /// Whether the model is in memory (it is unloaded after a while without use).
+    pub fn loaded(&self) -> bool {
+        #[cfg(feature = "sam")]
+        return self.worker.loaded();
+        #[cfg(not(feature = "sam"))]
+        false
+    }
+
+    /// Clicks waiting for their segmentation.
+    pub fn pending_clicks(&self) -> Option<&PendingClicks> {
+        self.pending.as_ref()
+    }
+
+    /// The model download's state.
+    pub fn download_status(&self) -> DownloadStatus {
+        #[cfg(feature = "sam")]
+        {
+            let s = self.download.status();
+            DownloadStatus { running: s.running, done: s.done, total: s.total, file: s.file, error: s.error, finished: s.finished }
+        }
+        #[cfg(not(feature = "sam"))]
+        DownloadStatus::default()
+    }
+
+    /// Where the model is downloaded from, in order (the user's mirrors first).
+    pub fn mirrors(&self) -> Vec<String> {
+        #[cfg(feature = "sam")]
+        {
+            let env = std::env::var(lightcraft_segment::fetch::MIRRORS_ENV).ok();
+            lightcraft_segment::fetch::mirrors(env.as_deref(), self.mirrors_file.as_deref())
+        }
+        #[cfg(not(feature = "sam"))]
+        Vec::new()
+    }
+
+    /// The model folder, if the model is there; otherwise an error that says what to do.
+    pub fn model_dir(&self) -> Result<PathBuf, String> {
+        if !Self::AVAILABLE {
+            return Err("AI masks are not available in this build".into());
+        }
+        let dir = self.dir.clone().ok_or("no folder is set for the SAM 3 model")?;
+        if self.installed() {
+            return Ok(dir);
+        }
+        let d = self.download_status();
+        if d.running {
+            let pct = d.done.saturating_mul(100).checked_div(d.total).unwrap_or(0);
+            return Err(format!("{NOT_INSTALLED} yet: it is downloading ({pct} %)."));
+        }
+        Err(format!(
+            "{NOT_INSTALLED}. Download it (about {:.1} GB, {LICENSE_NAME}) when LightCraft offers it, with `segment.model.download {{\"acknowledged\": true}}`, or put model.safetensors, vocab.json and merges.txt in {}.",
+            MODEL_BYTES as f64 / 1e9,
+            dir.display()
+        ))
+    }
+
+    /// Start downloading the model (on a background thread; see `segment.model.download`).
+    /// `Ok(false)` when it is installed or downloading already.
+    pub fn start_download(&self) -> Result<bool, String> {
+        if !Self::AVAILABLE {
+            return Err("AI masks are not available in this build".into());
+        }
+        let dir = self.dir.clone().ok_or("no folder is set for the SAM 3 model")?;
+        if self.installed() {
+            return Ok(false);
+        }
+        #[cfg(feature = "sam")]
+        {
+            let mirrors = self.mirrors();
+            if mirrors.is_empty() {
+                return Err(lightcraft_segment::fetch::DownloadError::NoMirrors.to_string());
+            }
+            self.download.start(lightcraft_segment::fetch::SAM3_FILES, mirrors, dir, lightcraft_segment::fetch::Options::default())
+        }
+        #[cfg(not(feature = "sam"))]
+        {
+            let _ = dir;
+            Ok(false)
+        }
+    }
+
+    /// Stop a running download (its partial files stay, to resume). False when none runs.
+    pub fn cancel_download(&self) -> bool {
+        #[cfg(feature = "sam")]
+        return self.download.cancel();
+        #[cfg(not(feature = "sam"))]
+        false
+    }
+}
+
+/// Mix `v` into a 64-bit hash.
+#[cfg_attr(not(feature = "sam"), allow(dead_code))]
+fn mix(h: u64, v: u64) -> u64 {
+    (h ^ v).wrapping_mul(0x0100_0000_01b3).rotate_left(29)
+}
+
+/// Objects covering more than this much of the photo gain little from a zoomed pass.
+const DETAIL_MAX_AREA: f64 = 0.4;
+
+/// The part of the photo to zoom into for `seg`'s selection: its bounding box with a margin of
+/// a quarter of its size, at least 12 % of the long edge, at most 2:1, inside the photo
+/// (`aspect` = width / height). `None` when nothing is selected or it is most of the photo.
+pub fn detail_region(seg: &SegMask, aspect: f64) -> Option<[f64; 4]> {
+    let logits = seg.logits()?;
+    let r = seg.bounds()?;
+    let side = seg.side as usize;
+    let (mut x0, mut y0, mut x1, mut y1) = (usize::MAX, usize::MAX, 0, 0);
+    for (i, l) in logits.iter().enumerate() {
+        if *l > 0.0 {
+            let (x, y) = (i % side, i / side);
+            (x0, y0, x1, y1) = (x0.min(x), y0.min(y), x1.max(x + 1), y1.max(y + 1));
+        }
+    }
+    if x0 == usize::MAX {
+        return None;
+    }
+    let (rw, rh) = (r[2] - r[0], r[3] - r[1]);
+    let nx = |c: usize| r[0] + c as f64 / side as f64 * rw;
+    let ny = |c: usize| r[1] + c as f64 / side as f64 * rh;
+    let (bx0, by0, bx1, by1) = (nx(x0), ny(y0), nx(x1), ny(y1));
+    if (bx1 - bx0) * (by1 - by0) > DETAIL_MAX_AREA {
+        return None;
+    }
+    // in units of the photo's height: x × aspect
+    let a = if aspect.is_finite() { aspect.clamp(0.1, 10.0) } else { 1.0 };
+    let (cx, cy) = ((bx0 + bx1) / 2.0 * a, (by0 + by1) / 2.0);
+    let size = ((bx1 - bx0) * a).max(by1 - by0);
+    let m = 0.25 * size;
+    let mut w = ((bx1 - bx0) * a + 2.0 * m).max(0.12 * a.max(1.0));
+    let mut h = ((by1 - by0) + 2.0 * m).max(0.12 * a.max(1.0));
+    w = w.max(h / 2.0).min(a);
+    h = h.max(w / 2.0).min(1.0);
+    let x = (cx - w / 2.0).clamp(0.0, (a - w).max(0.0));
+    let y = (cy - h / 2.0).clamp(0.0, (1.0 - h).max(0.0));
+    let out = [x / a, y, (x + w) / a, y + h];
+    // a region nearly the whole photo isn't worth a second pass
+    ((out[2] - out[0]) * (out[3] - out[1]) < 0.8).then_some(out)
+}
+
+/// `shape` without its detail patches (what a detail pass was computed from)
+#[cfg_attr(not(feature = "sam"), allow(dead_code))]
+fn strip_detail(mut shape: MaskShape) -> MaskShape {
+    // (nor its edge setting: moving the slider meanwhile keeps the pass)
+    if let MaskShape::Object { detail, edge, .. } | MaskShape::Prompt { detail, edge, .. } = &mut shape {
+        detail.clear();
+        *edge = 0.0;
+    }
+    shape
+}
+
+fn clicks_of(include: &[Point], exclude: &[Point]) -> Vec<Click> {
+    include.iter().map(|p| Click { at: *p, include: true }).chain(exclude.iter().map(|p| Click { at: *p, include: false })).collect()
+}
+
+impl Session {
+    /// The key and settings of photo `id` as the model sees it: its look without masks, uncropped.
+    #[cfg_attr(not(feature = "sam"), allow(dead_code))]
+    fn segment_key(&self, id: PhotoId) -> Option<(u64, lightcraft_develop::DevelopSettings)> {
+        let p = self.catalog.photo(id)?;
+        let mut d = (*p.develop).clone();
+        d.masks.clear();
+        let content = crate::media::content_key(p);
+        let mut h = mix(0xcbf2_9ce4_8422_2325, d.hash64());
+        h = mix(h, id.0);
+        for b in content.bytes() {
+            h = mix(h, u64::from(b));
+        }
+        Some((h, d))
+    }
+
+    /// Clicks (in normalized photo coordinates) for the model.
+    #[cfg(feature = "sam")]
+    fn model_clicks(clicks: &[Click]) -> Vec<lightcraft_segment::Click> {
+        clicks.iter().map(|c| lightcraft_segment::Click { x: c.at.x as f32, y: c.at.y as f32, positive: c.include }).collect()
+    }
+
+    /// A worker request about photo `id` (the render job for its model input goes along; the
+    /// worker runs it only when its cache doesn't hold the photo). `region` renders that part
+    /// of the photo, from a source sharp enough for it (detail passes).
+    #[cfg(feature = "sam")]
+    fn segment_job(
+        &mut self,
+        id: PhotoId,
+        kind: worker::Kind,
+        tag: Tag,
+        reply: std::sync::mpsc::Sender<worker::Outcome>,
+        region: Option<[f64; 4]>,
+    ) -> Result<worker::Job, String> {
+        let dir = self.segmenter.model_dir()?;
+        let (key, mut d) = self.segment_key(id).ok_or("no such photo")?;
+        let p = self.catalog.photo(id).ok_or("no such photo")?.clone();
+        let missing = match &p.source {
+            lightcraft_catalog::Source::File { path } if !std::path::Path::new(path).exists() => Some(path.clone()),
+            _ => None,
+        };
+        let render = match region {
+            None => self.preview_job(id, INPUT_EDGE, INPUT_EDGE, false, &d).ok_or("no such photo")?,
+            Some(region) => {
+                d.crop.geometry =
+                    lightcraft_geom::CropGeometry { rect: lightcraft_geom::Rect::new(region[0], region[1], region[2], region[3]), angle: 0.0 };
+                d.crop.flip_h = false;
+                d.crop.flip_v = false;
+                d.geometry.constrain_crop = false;
+                let mut job = self.preview_job(id, INPUT_EDGE, INPUT_EDGE, true, &d).ok_or("no such photo")?;
+                let frac = (region[2] - region[0]).max(region[3] - region[1]).max(0.01);
+                job.level = crate::media::SourceLevel::for_size((INPUT_EDGE as f64 / frac) as usize);
+                job.source = self.media.source_ref(&p, job.level);
+                job
+            }
+        };
+        Ok(worker::Job { dir, key: if region.is_some() { 0 } else { key }, render: Some(render), missing, kind, tag, reply })
+    }
+
+    /// Send a request and wait for its result (CLI, MCP, tests; or when not in background mode).
+    #[cfg(feature = "sam")]
+    fn segment_wait(&mut self, id: PhotoId, kind: worker::Kind, region: Option<[f64; 4]>) -> Result<Option<SegMask>, String> {
+        let (tx, rx) = std::sync::mpsc::channel();
+        let job = self.segment_job(id, kind, Tag::Wait, tx, region)?;
+        self.segmenter.worker.submit(job)?;
+        match rx.recv_timeout(WAIT) {
+            Ok(o) => o.result,
+            Err(_) => Err("the AI model took too long; try again".into()),
+        }
+    }
+
+    /// Send a request whose result [`Session::segment_poll`] applies.
+    #[cfg(feature = "sam")]
+    fn segment_queue(&mut self, id: PhotoId, kind: worker::Kind, tag: Tag, region: Option<[f64; 4]>) -> Result<(), String> {
+        let reply = self.segmenter.results.0.clone();
+        let job = self.segment_job(id, kind, tag, reply, region)?;
+        self.segmenter.worker.submit(job)
+    }
+
+    /// Start preparing photo `id` for AI masks (load the model, encode the image), so the first
+    /// click is fast. In background mode it returns at once.
+    pub fn segment_prepare(&mut self, id: PhotoId) -> Result<(), String> {
+        self.segmenter.model_dir()?;
+        #[cfg(feature = "sam")]
+        {
+            if self.segmenter.background {
+                return self.segment_queue(id, worker::Kind::Prepare, Tag::Prepare, None);
+            }
+            self.segment_wait(id, worker::Kind::Prepare, None)?;
+        }
+        #[cfg(not(feature = "sam"))]
+        let _ = id;
+        Ok(())
+    }
+
+    /// Segment the object `clicks` pick on photo `id`, waiting for the model.
+    pub fn segment_clicks(&mut self, id: PhotoId, clicks: &[Click]) -> Result<SegMask, String> {
+        self.segmenter.model_dir()?;
+        if !clicks.iter().any(|c| c.include) {
+            return Err("click the object to include it first".into());
+        }
+        #[cfg(feature = "sam")]
+        {
+            self.segment_wait(id, worker::Kind::Clicks(Self::model_clicks(clicks)), None)?.ok_or_else(|| "nothing was selected".to_string())
+        }
+        #[cfg(not(feature = "sam"))]
+        {
+            let _ = id;
+            Err("AI masks are not available in this build".into())
+        }
+    }
+
+    /// Segment everything `text` describes on photo `id`, waiting for the model; `Ok(None)`
+    /// when nothing matches.
+    pub fn segment_text(&mut self, id: PhotoId, text: &str) -> Result<Option<SegMask>, String> {
+        self.segmenter.model_dir()?;
+        let text = text.trim();
+        if text.is_empty() {
+            return Err("describe what to select".into());
+        }
+        #[cfg(feature = "sam")]
+        {
+            self.segment_wait(id, worker::Kind::Text(text.to_string()), None)
+        }
+        #[cfg(not(feature = "sam"))]
+        {
+            let _ = id;
+            Err("AI masks are not available in this build".into())
+        }
+    }
+
+    /// Background mode: queue Object clicks for component `comp` of mask `mask`; the result
+    /// (clicks and segmentation, one undo step) is applied by [`Session::segment_poll`].
+    pub(crate) fn segment_clicks_later(&mut self, id: PhotoId, mask: u32, comp: usize, hint: Vec<Point>, exclude: Vec<Point>) -> Result<(), String> {
+        self.segmenter.model_dir()?;
+        if hint.is_empty() {
+            return Err("click the object to include it first".into());
+        }
+        #[cfg(feature = "sam")]
+        {
+            let clicks = Self::model_clicks(&clicks_of(&hint, &exclude));
+            let tag = Tag::Clicks { photo: id, mask, comp, hint: hint.clone(), exclude: exclude.clone() };
+            self.segment_queue(id, worker::Kind::Clicks(clicks), tag, None)?;
+            self.segmenter.pending = Some(PendingClicks { photo: id, mask, comp, hint, exclude });
+            Ok(())
+        }
+        #[cfg(not(feature = "sam"))]
+        {
+            let _ = (id, mask, comp, exclude);
+            Err("AI masks are not available in this build".into())
+        }
+    }
+
+    /// Background mode: queue a Describe selection; the mask (or component, combined by `op`
+    /// into mask `mask`) is created by [`Session::segment_poll`] when something matches.
+    pub(crate) fn segment_text_later(&mut self, id: PhotoId, mask: Option<u32>, op: &str, name: Option<String>, text: &str) -> Result<(), String> {
+        self.segmenter.model_dir()?;
+        let text = text.trim();
+        if text.is_empty() {
+            return Err("describe what to select".into());
+        }
+        #[cfg(feature = "sam")]
+        {
+            let tag = Tag::NewPrompt { photo: id, mask, op: op.to_string(), name, text: text.to_string() };
+            self.segment_queue(id, worker::Kind::Text(text.to_string()), tag, None)
+        }
+        #[cfg(not(feature = "sam"))]
+        {
+            let _ = (id, mask, op, name);
+            Err("AI masks are not available in this build".into())
+        }
+    }
+
+    /// Start a zoomed-in pass for component `comp` of mask `mask` on photo `id` (an Object or
+    /// Describe selection): the photo around the selection is rendered at a higher resolution
+    /// and segmented again. In background mode [`Session::segment_poll`] applies the result;
+    /// otherwise it is applied before this returns. `Ok(false)` when there is nothing to
+    /// refine (no selection yet, or it is most of the photo) or a pass is running already.
+    pub fn segment_detail(&mut self, id: PhotoId, mask: u32, comp: usize) -> Result<bool, String> {
+        self.segmenter.model_dir()?;
+        let d = self.develop_of(id).ok_or("no such photo")?;
+        let shape = d.masks.iter().find(|m| m.id == mask).and_then(|m| m.components.get(comp)).map(|c| c.shape.clone()).ok_or("no such mask")?;
+        let (seg, prompt) = match &shape {
+            // (a document with absurdly many clicks isn't run through the model)
+            MaskShape::Object { hint, exclude, seg: Some(seg), .. } if !hint.is_empty() && hint.len() + exclude.len() <= MAX_CLICKS => {
+                (seg.clone(), Prompt::Clicks(clicks_of(hint, exclude)))
+            }
+            MaskShape::Prompt { text, seg: Some(seg), .. } => (seg.clone(), Prompt::Text(text.clone())),
+            _ => return Ok(false),
+        };
+        let p = self.catalog.photo(id).ok_or("no such photo")?;
+        let (pw, ph) = (f64::from(p.width.max(1)), f64::from(p.height.max(1)));
+        let aspect = if d.orientation.swaps_axes() { ph / pw } else { pw / ph };
+        let Some(region) = detail_region(&seg, aspect) else { return Ok(false) };
+        #[cfg(feature = "sam")]
+        {
+            let kind = worker::Kind::Detail { prompt, region };
+            let tag = Tag::Detail { photo: id, mask, comp, shape: strip_detail(shape) };
+            if self.segmenter.background {
+                if self.segmenter.detail_busy() {
+                    return Ok(false);
+                }
+                self.segment_queue(id, kind, tag, Some(region))?;
+            } else {
+                let patch = self.segment_wait(id, kind, Some(region))?;
+                let outcome = worker::Outcome { tag, result: Ok(patch), superseded: false };
+                let mut polled = Polled::default();
+                self.apply_outcome(outcome, &mut polled);
+            }
+            Ok(true)
+        }
+        #[cfg(not(feature = "sam"))]
+        {
+            let _ = (prompt, region, mask);
+            Ok(false)
+        }
+    }
+
+    /// Apply finished background requests (to masks that haven't changed since) and collect
+    /// their messages. Cheap when nothing is pending: call it every frame.
+    pub fn segment_poll(&mut self) -> Polled {
+        #[cfg_attr(not(feature = "sam"), allow(unused_mut))]
+        let mut polled = Polled { messages: std::mem::take(&mut self.segmenter.messages), ..Default::default() };
+        #[cfg(feature = "sam")]
+        {
+            // (before draining: a worker that is idle now has sent everything)
+            let idle = !self.segmenter.busy();
+            let done: Vec<worker::Outcome> = self.segmenter.results.1.try_iter().collect();
+            for o in done {
+                self.apply_outcome(o, &mut polled);
+            }
+            // clicks whose request was lost (the worker restarted) aren't pending forever
+            if idle {
+                self.segmenter.pending = None;
+            }
+        }
+        polled
+    }
+
+    #[cfg(feature = "sam")]
+    fn apply_outcome(&mut self, o: worker::Outcome, polled: &mut Polled) {
+        if o.superseded {
+            return;
+        }
+        match o.tag {
+            Tag::Wait => {}
+            Tag::Prepare => {
+                if let Err(e) = o.result {
+                    polled.messages.push(e);
+                }
+            }
+            Tag::Clicks { photo, mask, comp, hint, exclude } => {
+                let latest = PendingClicks { photo, mask, comp, hint, exclude };
+                if self.segmenter.pending.as_ref() != Some(&latest) {
+                    return; // newer clicks are on their way
+                }
+                self.segmenter.pending = None;
+                let seg = match o.result {
+                    Ok(Some(seg)) => seg,
+                    Ok(None) => return,
+                    Err(e) => return polled.messages.push(e),
+                };
+                let Some(d) = self.develop_of(photo) else { return };
+                let mut d = (*d).clone();
+                let Some(c) = d.masks.iter_mut().find(|m| m.id == mask).and_then(|m| m.components.get_mut(comp)) else { return };
+                let MaskShape::Object { edge, .. } = c.shape else { return };
+                c.shape = MaskShape::Object { hint: latest.hint, exclude: latest.exclude, seg: Some(seg), detail: vec![], edge };
+                match self.set_develop(photo, d, "Object Mask") {
+                    Ok(()) => {
+                        polled.changed = true;
+                        polled.refine = Some(mask);
+                    }
+                    Err(e) => polled.messages.push(e.to_string()),
+                }
+            }
+            Tag::NewPrompt { photo, mask, op, name, text } => {
+                let seg = match o.result {
+                    Ok(Some(seg)) => seg,
+                    Ok(None) => return polled.messages.push(format!("Nothing matching “{text}” was found in this photo.")),
+                    Err(e) => return polled.messages.push(e),
+                };
+                if self.active() != Some(photo) {
+                    return polled.messages.push(format!("The photo changed before “{text}” was found; try again."));
+                }
+                let Ok(seg) = serde_json::to_value(seg) else { return };
+                let mut p = serde_json::json!({"kind": "prompt", "text": text, "seg": seg});
+                if let Some(n) = name {
+                    p["name"] = serde_json::json!(n);
+                }
+                let r = match mask {
+                    None => self.execute("mask.add", &p),
+                    Some(m) => {
+                        if !self.develop_of(photo).is_some_and(|d| d.masks.iter().any(|x| x.id == m)) {
+                            return polled.messages.push("The mask was removed before the selection was found.".into());
+                        }
+                        self.active_mask = Some(m);
+                        p["op"] = serde_json::json!(op);
+                        self.execute("mask.addComponent", &p)
+                    }
+                };
+                match r {
+                    Ok(_) => {
+                        polled.changed = true;
+                        polled.refine = self.active_mask;
+                    }
+                    Err(e) => polled.messages.push(e.to_string()),
+                }
+            }
+            Tag::Detail { photo, mask, comp, shape } => {
+                let patch = match o.result {
+                    Ok(Some(p)) => p,
+                    Ok(None) => return,
+                    Err(e) => return log::warn!("SAM 3 detail pass: {e}"),
+                };
+                let Some(d) = self.develop_of(photo) else { return };
+                let mut d = (*d).clone();
+                let Some(c) = d.masks.iter_mut().find(|m| m.id == mask).and_then(|m| m.components.get_mut(comp)) else { return };
+                if strip_detail(c.shape.clone()) != shape {
+                    return; // clicked again meanwhile: a newer pass will follow
+                }
+                match &mut c.shape {
+                    MaskShape::Object { detail, .. } | MaskShape::Prompt { detail, .. } => *detail = vec![patch],
+                    _ => return,
+                }
+                match self.set_develop(photo, d, "AI Mask Detail") {
+                    Ok(()) => polled.changed = true,
+                    Err(e) => log::warn!("AI mask detail: {e}"),
+                }
+            }
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn seg_box(side: usize, x0: usize, y0: usize, x1: usize, y1: usize) -> SegMask {
+        let l: Vec<f32> =
+            (0..side * side).map(|i| if (x0..x1).contains(&(i % side)) && (y0..y1).contains(&(i / side)) { 8.0 } else { -8.0 }).collect();
+        SegMask::from_logits(side, &l)
+    }
+
+    #[test]
+    fn detail_region_frames_the_selection_with_a_margin() {
+        // a small object in the middle of a square photo
+        let r = detail_region(&seg_box(100, 40, 45, 50, 55), 1.0).unwrap();
+        assert!(r[0] < 0.4 && r[2] > 0.5 && r[1] < 0.45 && r[3] > 0.55, "contains it: {r:?}");
+        assert!(r[2] - r[0] < 0.25 && r[3] - r[1] < 0.25, "zoomed in: {r:?}");
+        assert!(r.iter().all(|v| (0.0..=1.0).contains(v)));
+        // at the corner: shifted inside the photo, not cut
+        let r = detail_region(&seg_box(100, 0, 0, 5, 5), 1.5).unwrap();
+        assert!(r[0] >= 0.0 && r[1] >= 0.0 && r[0] < 1e-9 && r[1] < 1e-9);
+        // a thin object stays at most 2:1 (in photo pixels, 1.5:1 photo)
+        let r = detail_region(&seg_box(100, 10, 50, 90, 52), 1.5).unwrap();
+        let (w, h) = ((r[2] - r[0]) * 1.5, r[3] - r[1]);
+        assert!(w / h <= 2.0 + 1e-9, "{w} × {h}");
+        // a hostile aspect ratio stays sane
+        assert!(detail_region(&seg_box(100, 40, 45, 50, 55), f64::NAN).is_some_and(|r| r.iter().all(|v| v.is_finite())));
+    }
+
+    #[test]
+    fn no_region_for_nothing_or_most_of_the_photo() {
+        assert!(detail_region(&seg_box(50, 0, 0, 0, 0), 1.0).is_none());
+        assert!(detail_region(&seg_box(50, 2, 2, 48, 48), 1.0).is_none());
+        let damaged = SegMask { side: 50, data: "?".into(), rect: None };
+        assert!(detail_region(&damaged, 1.0).is_none());
+    }
+}

crates/engine/src/segment/worker.rs

@@ -0,0 +1,426 @@
+//! The SAM 3 worker thread: it owns the model and the last encoded photo, and runs every
+//! request (load, render the model input, encode, clicks, descriptions, detail passes) in
+//! turn. The session only sends jobs and receives outcomes over channels, so no thread ever
+//! waits on a lock the model holds, and the UI thread never runs the model.
+//!
+//! Every job runs under `catch_unwind`: a panic inside candle becomes an error outcome, drops
+//! the (possibly inconsistent) model and leaves the worker ready for the next job. The busy
+//! counters are decremented by drop guards, so they can't stay stuck. The model is unloaded
+//! after [`IDLE_UNLOAD`] without requests (it holds several GB).
+
+use std::collections::VecDeque;
+use std::panic::AssertUnwindSafe;
+use std::path::PathBuf;
+use std::sync::Arc;
+use std::sync::atomic::{AtomicBool, AtomicUsize, Ordering};
+use std::sync::mpsc::{self, RecvTimeoutError};
+use std::time::Duration;
+
+use lightcraft_develop::SegMask;
+use lightcraft_segment::{Encoded, Sam3};
+
+use super::{Input, Prompt, Tag};
+use crate::media::RenderJob;
+
+/// Unload the model after this long without a request.
+pub const IDLE_UNLOAD: Duration = Duration::from_secs(10 * 60);
+
+/// What to compute.
+pub enum Kind {
+    /// Load the model and encode the photo (so the first click is fast).
+    Prepare,
+    Clicks(Vec<lightcraft_segment::Click>),
+    Text(String),
+    /// A zoomed-in pass over `region` (normalized) of the photo, rendered by the job's `render`.
+    Detail {
+        prompt: Prompt,
+        region: [f64; 4],
+    },
+    /// Panics (tests of the worker's recovery).
+    #[cfg(test)]
+    Panic,
+}
+
+/// One request.
+pub struct Job {
+    /// The model folder.
+    pub dir: PathBuf,
+    /// Which photo and look the request is about (the encode cache's key).
+    pub key: u64,
+    /// Renders the model input when the cache doesn't hold `key` (always for a detail pass).
+    pub render: Option<RenderJob>,
+    /// The photo's file, when it is missing on disk (for a clearer error if rendering fails).
+    pub missing: Option<String>,
+    pub kind: Kind,
+    pub tag: Tag,
+    pub reply: mpsc::Sender<Outcome>,
+}
+
+/// A finished request: the segmentation (`None`: nothing selected / nothing to report).
+pub struct Outcome {
+    pub tag: Tag,
+    pub result: Result<Option<SegMask>, String>,
+    /// A newer request for the same selection came in; this one was skipped.
+    pub superseded: bool,
+}
+
+/// Counters the session reads without locking.
+#[derive(Default)]
+pub struct Shared {
+    /// Requests other than detail passes, queued or running.
+    pub pending: AtomicUsize,
+    /// Detail passes queued or running.
+    pub detail: AtomicUsize,
+    /// The model is in memory.
+    pub loaded: AtomicBool,
+    /// Loading the model or encoding a photo right now (the slow parts).
+    pub encoding: AtomicBool,
+}
+
+/// Decrements a counter when dropped (also when unwinding).
+struct Done<'a>(&'a AtomicUsize);
+
+impl Drop for Done<'_> {
+    fn drop(&mut self) {
+        let _ = self.0.try_update(Ordering::SeqCst, Ordering::SeqCst, |n| Some(n.saturating_sub(1)));
+    }
+}
+
+/// Sets a flag while alive.
+struct Flag<'a>(&'a AtomicBool);
+
+impl<'a> Flag<'a> {
+    fn raise(f: &'a AtomicBool) -> Self {
+        f.store(true, Ordering::SeqCst);
+        Flag(f)
+    }
+}
+
+impl Drop for Flag<'_> {
+    fn drop(&mut self) {
+        self.0.store(false, Ordering::SeqCst);
+    }
+}
+
+/// The session's handle on the worker thread (started on the first request, restarted if it
+/// ever ends).
+#[derive(Default)]
+pub struct Worker {
+    tx: Option<mpsc::Sender<Job>>,
+    thread: Option<std::thread::JoinHandle<()>>,
+    pub shared: Arc<Shared>,
+}
+
+impl Worker {
+    fn counter(&self, job: &Job) -> &AtomicUsize {
+        if matches!(job.kind, Kind::Detail { .. }) { &self.shared.detail } else { &self.shared.pending }
+    }
+
+    /// Whether the thread has ended (it never should); its counters are then meaningless.
+    fn dead(&self) -> bool {
+        self.thread.as_ref().is_some_and(|t| t.is_finished())
+    }
+
+    pub fn pending(&self) -> usize {
+        if self.dead() { 0 } else { self.shared.pending.load(Ordering::SeqCst) }
+    }
+
+    pub fn detail(&self) -> usize {
+        if self.dead() { 0 } else { self.shared.detail.load(Ordering::SeqCst) }
+    }
+
+    pub fn encoding(&self) -> bool {
+        !self.dead() && self.shared.encoding.load(Ordering::SeqCst)
+    }
+
+    pub fn loaded(&self) -> bool {
+        !self.dead() && self.shared.loaded.load(Ordering::SeqCst)
+    }
+
+    /// Queue `job`; returns at once.
+    pub fn submit(&mut self, job: Job) -> Result<(), String> {
+        if self.dead() {
+            // a thread that ended took its counters' meaning with it
+            self.tx = None;
+            self.thread = None;
+            self.shared = Arc::new(Shared::default());
+        }
+        self.counter(&job).fetch_add(1, Ordering::SeqCst);
+        let job = match &self.tx {
+            Some(tx) => match tx.send(job) {
+                Ok(()) => return Ok(()),
+                Err(mpsc::SendError(job)) => job,
+            },
+            None => job,
+        };
+        // (re)start the thread
+        let (tx, rx) = mpsc::channel();
+        let shared = self.shared.clone();
+        match std::thread::Builder::new().name("sam3".into()).spawn(move || run(&rx, &shared, IDLE_UNLOAD)) {
+            Ok(t) => {
+                self.thread = Some(t);
+                self.tx = Some(tx.clone());
+                tx.send(job).map_err(|_| "the AI mask worker stopped".to_string())
+            }
+            Err(e) => {
+                let _ = self.counter(&job).try_update(Ordering::SeqCst, Ordering::SeqCst, |n| Some(n.saturating_sub(1)));
+                Err(format!("could not start the AI mask worker: {e}"))
+            }
+        }
+    }
+}
+
+/// The model and the last encoded photo.
+#[derive(Default)]
+struct State {
+    model: Option<(PathBuf, Sam3)>,
+    cache: Option<(u64, Encoded)>,
+}
+
+/// Whether `later` makes `job` pointless (it asks for the same selection again).
+fn supersedes(later: &Job, job: &Job) -> bool {
+    match (&later.tag, &job.tag) {
+        (Tag::Prepare, Tag::Prepare) => later.key == job.key,
+        (Tag::Clicks { photo: a, mask: am, comp: ac, .. }, Tag::Clicks { photo: b, mask: bm, comp: bc, .. }) => (a, am, ac) == (b, bm, bc),
+        (Tag::Detail { photo: a, mask: am, comp: ac, .. }, Tag::Detail { photo: b, mask: bm, comp: bc, .. }) => (a, am, ac) == (b, bm, bc),
+        _ => false,
+    }
+}
+
+fn run(rx: &mpsc::Receiver<Job>, shared: &Shared, idle: Duration) {
+    let mut state = State::default();
+    let mut queue: VecDeque<Job> = VecDeque::new();
+    loop {
+        if queue.is_empty() {
+            match rx.recv_timeout(idle) {
+                Ok(j) => queue.push_back(j),
+                Err(RecvTimeoutError::Timeout) => {
+                    if state.model.is_some() {
+                        state = State::default();
+                        shared.loaded.store(false, Ordering::SeqCst);
+                        log::info!("SAM 3 unloaded after {} minutes without use", idle.as_secs() / 60);
+                    }
+                    continue;
+                }
+                Err(RecvTimeoutError::Disconnected) => return,
+            }
+        }
+        while let Ok(j) = rx.try_recv() {
+            queue.push_back(j);
+        }
+        let Some(mut job) = queue.pop_front() else { continue };
+        let is_detail = matches!(job.kind, Kind::Detail { .. });
+        let _done = Done(if is_detail { &shared.detail } else { &shared.pending });
+        if queue.iter().any(|later| supersedes(later, &job)) {
+            let _ = job.reply.send(Outcome { tag: job.tag, result: Ok(None), superseded: true });
+            continue;
+        }
+        let result = match std::panic::catch_unwind(AssertUnwindSafe(|| run_job(&mut state, shared, &mut job))) {
+            Ok(r) => r,
+            Err(p) => {
+                let why = p.downcast_ref::<&str>().map(|s| s.to_string()).or_else(|| p.downcast_ref::<String>().cloned()).unwrap_or_default();
+                log::error!("SAM 3 panicked: {why}");
+                // don't trust what the model kept: load it again next time
+                state = State::default();
+                Err("the AI model failed unexpectedly (it will be reloaded on the next try)".to_string())
+            }
+        };
+        if result.is_err() && !is_detail {
+            state.cache = None;
+        }
+        shared.loaded.store(state.model.is_some(), Ordering::SeqCst);
+        let _ = job.reply.send(Outcome { tag: job.tag, result, superseded: false });
+    }
+}
+
+/// The model for `dir`, loading it when needed.
+fn model<'a>(state: &'a mut State, shared: &Shared, dir: &std::path::Path) -> Result<&'a mut Sam3, String> {
+    if state.model.as_ref().is_none_or(|(d, _)| d != dir) {
+        state.model = None;
+        state.cache = None;
+        let _busy = Flag::raise(&shared.encoding);
+        let t = web_time::Instant::now();
+        let m = Sam3::load(dir).map_err(|e| e.to_string())?;
+        log::info!("SAM 3 loaded in {:?}", t.elapsed());
+        state.model = Some((dir.to_path_buf(), m));
+        shared.loaded.store(true, Ordering::SeqCst);
+    }
+    state.model.as_mut().map(|(_, m)| m).ok_or_else(|| "the model did not load".to_string())
+}
+
+/// Render the model input.
+fn render(job: &mut Job) -> Result<Input, String> {
+    let r = job.render.take().ok_or("the photo is not available")?.run();
+    let img = match r.rendered {
+        Ok(r) => r.image,
+        Err(e) => {
+            return Err(match &job.missing {
+                Some(path) => format!(
+                    "This photo's file is missing (moved or deleted), so it can't be analyzed for AI masks: {path}. Library ▸ Find Missing Photos can relink it."
+                ),
+                None => format!("couldn't render the photo for AI masks: {e}"),
+            });
+        }
+    };
+    let rgb = img.data.iter().flat_map(|p| [p[0], p[1], p[2]]).collect();
+    Ok(Input { rgb, w: img.width, h: img.height })
+}
+
+/// The model and the encoded photo `job.key` (rendering and encoding it when needed).
+fn encoded<'a>(state: &'a mut State, shared: &Shared, job: &mut Job) -> Result<(&'a mut Sam3, &'a mut Encoded), String> {
+    model(state, shared, &job.dir)?;
+    if state.cache.as_ref().is_none_or(|(k, _)| *k != job.key) {
+        state.cache = None;
+        let input = render(job)?;
+        let _busy = Flag::raise(&shared.encoding);
+        let m = state.model.as_mut().map(|(_, m)| m).ok_or("the model did not load")?;
+        let t = web_time::Instant::now();
+        let mut enc = m.encode(&input.rgb, input.w, input.h).map_err(|e| e.to_string())?;
+        m.prepare_clicks(&mut enc).map_err(|e| e.to_string())?;
+        log::info!("SAM 3 encoded {}×{} in {:?}", input.w, input.h, t.elapsed());
+        state.cache = Some((job.key, enc));
+    }
+    let State { model, cache } = state;
+    match (model.as_mut(), cache.as_mut()) {
+        (Some((_, m)), Some((_, e))) => Ok((m, e)),
+        _ => Err("the model is not ready".into()),
+    }
+}
+
+/// Every phrase of `text` ("car, road"), merged (the per-pixel maximum); `None` when nothing
+/// matches.
+fn text_logits(model: &mut Sam3, enc: &mut Encoded, text: &str) -> Result<Option<Vec<f32>>, String> {
+    let mut merged: Option<Vec<f32>> = None;
+    for phrase in text.split([',', ';']).map(str::trim).filter(|p| !p.is_empty()) {
+        if let Some(p) = model.segment_text(enc, phrase, 0.5).map_err(|e| e.to_string())? {
+            merged = Some(match merged {
+                None => p.logits,
+                Some(m) => m.iter().zip(&p.logits).map(|(a, b)| a.max(*b)).collect(),
+            });
+        }
+    }
+    Ok(merged)
+}
+
+fn run_job(state: &mut State, shared: &Shared, job: &mut Job) -> Result<Option<SegMask>, String> {
+    let side = lightcraft_segment::MASK_SIDE;
+    match std::mem::replace(&mut job.kind, Kind::Prepare) {
+        Kind::Prepare => {
+            encoded(state, shared, job)?;
+            Ok(None)
+        }
+        Kind::Clicks(clicks) => {
+            let (m, enc) = encoded(state, shared, job)?;
+            let p = m.segment_clicks(enc, &clicks).map_err(|e| e.to_string())?;
+            Ok(Some(SegMask::from_logits(side, &p.logits)))
+        }
+        Kind::Text(text) => {
+            let (m, enc) = encoded(state, shared, job)?;
+            Ok(text_logits(m, enc, &text)?.map(|l| SegMask::from_logits(side, &l)))
+        }
+        #[cfg(test)]
+        #[allow(clippy::panic)]
+        Kind::Panic => panic!("a test panic"),
+        Kind::Detail { prompt, region } => {
+            let input = render(job)?;
+            let m = model(state, shared, &job.dir)?;
+            let t = web_time::Instant::now();
+            let mut enc = m.encode(&input.rgb, input.w, input.h).map_err(|e| e.to_string())?;
+            let (rw, rh) = (region[2] - region[0], region[3] - region[1]);
+            if !(rw > 0.0 && rh > 0.0) {
+                return Ok(None);
+            }
+            let logits = match prompt {
+                Prompt::Clicks(clicks) => {
+                    let inside: Vec<lightcraft_segment::Click> = clicks
+                        .iter()
+                        .map(|c| ((c.at.x - region[0]) / rw, (c.at.y - region[1]) / rh, c.include))
+                        .filter(|(x, y, _)| (0.0..=1.0).contains(x) && (0.0..=1.0).contains(y))
+                        .map(|(x, y, positive)| lightcraft_segment::Click { x: x as f32, y: y as f32, positive })
+                        .collect();
+                    if !inside.iter().any(|c| c.positive) {
+                        return Ok(None);
+                    }
+                    Some(m.segment_clicks(&mut enc, &inside).map_err(|e| e.to_string())?.logits)
+                }
+                Prompt::Text(text) => text_logits(m, &mut enc, &text)?,
+            };
+            log::info!("SAM 3 detail pass ({}×{}) in {:?}", input.w, input.h, t.elapsed());
+            Ok(logits.map(|l| SegMask::from_logits_in(side, &l, region)))
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn job(tag: Tag, reply: &mpsc::Sender<Outcome>) -> Job {
+        // an empty folder: loading fails with an error (no model files)
+        let dir = std::env::temp_dir().join(format!("lc-sam3-worker-none-{}", std::process::id()));
+        Job { dir, key: 1, render: None, missing: None, kind: Kind::Prepare, tag, reply: reply.clone() }
+    }
+
+    #[test]
+    fn errors_come_back_and_the_counters_return_to_zero() {
+        let mut w = Worker::default();
+        let (tx, rx) = mpsc::channel();
+        for _ in 0..3 {
+            w.submit(job(Tag::Wait, &tx)).unwrap();
+        }
+        for _ in 0..3 {
+            let o = rx.recv_timeout(Duration::from_secs(30)).unwrap();
+            assert!(o.result.unwrap_err().contains("not found"));
+        }
+        let t = web_time::Instant::now();
+        while w.pending() > 0 && t.elapsed() < Duration::from_secs(5) {
+            std::thread::yield_now();
+        }
+        assert_eq!(w.pending(), 0);
+        assert!(!w.encoding() && !w.loaded());
+    }
+
+    #[test]
+    fn a_panic_in_a_job_is_an_error_and_the_worker_carries_on() {
+        let shared = Shared::default();
+        let (tx, rx) = mpsc::channel();
+        let (jtx, jrx) = mpsc::channel();
+        let mut j = job(Tag::Wait, &tx);
+        j.kind = Kind::Panic;
+        jtx.send(j).unwrap();
+        jtx.send(job(Tag::Wait, &tx)).unwrap();
+        shared.pending.store(2, Ordering::SeqCst);
+        drop(jtx);
+        run(&jrx, &shared, Duration::from_secs(60));
+        let first = rx.recv().unwrap();
+        assert!(first.result.unwrap_err().contains("failed unexpectedly"));
+        let second = rx.recv().unwrap();
+        assert!(second.result.is_err(), "the next job still runs");
+        assert_eq!(shared.pending.load(Ordering::SeqCst), 0, "counters reset");
+        assert!(!shared.encoding.load(Ordering::SeqCst));
+    }
+
+    #[test]
+    fn a_newer_request_for_the_same_selection_supersedes_a_queued_one() {
+        let (tx, rx) = mpsc::channel();
+        let (jtx, jrx) = mpsc::channel();
+        let clicks = |n: usize| Tag::Clicks {
+            photo: lightcraft_catalog::PhotoId(1),
+            mask: 1,
+            comp: 0,
+            hint: vec![lightcraft_geom::Point::new(0.5, 0.5); n],
+            exclude: vec![],
+        };
+        for n in 1..=3 {
+            jtx.send(job(clicks(n), &tx)).unwrap();
+        }
+        drop(jtx);
+        let shared = Shared::default();
+        shared.pending.store(3, Ordering::SeqCst);
+        run(&jrx, &shared, Duration::from_secs(60));
+        let out: Vec<Outcome> = rx.try_iter().collect();
+        assert_eq!(out.len(), 3);
+        assert!(out[0].superseded && out[1].superseded && !out[2].superseded);
+        assert_eq!(shared.pending.load(Ordering::SeqCst), 0);
+    }
+}

crates/engine/src/sidecar.rs

@@ -99,6 +99,7 @@ pub struct SidecarData {
     pub alt_text: Option<String>,
     pub extended_description: Option<String>,
     pub keywords: Option<Vec<String>>,
+    pub regions: Option<Vec<lightcraft_meta::Region>>,
     /// Capture time (ISO 8601) from `exif:DateTimeOriginal`, `photoshop:DateCreated` or
     /// `xmp:CreateDate` (first found). Used only when the file itself has no capture time.
     pub captured: Option<String>,
@@ -133,6 +134,12 @@ pub fn parse_sidecar(xmp: &str, raw: bool) -> std::result::Result<SidecarData, S
         alt_text: m.alt_text.clone(),
         extended_description: m.extended_description.clone(),
         keywords: (!m.keywords.is_empty()).then(|| m.keywords.clone()),
+        // A sidecar that has `mwg-rs:Regions` at all (even an empty list) was written by an app that
+        // knows about regions, so it's authoritative: its list, empty or not, replaces the catalog's.
+        // One without it (most writers, LightCraft's own included, which keeps another app's
+        // `mwg-rs:Regions` byte for byte but never writes one) says nothing about regions, and the
+        // photo's are kept.
+        regions: d.values.contains_key("mwg-rs:Regions").then(|| m.regions.clone()),
         captured: m.capture_time.map(|d| d.to_iso()),
         ..Default::default()
     };
@@ -202,6 +209,9 @@ pub fn merge_into(p: &mut Photo, sc: &SidecarData, now: &str) -> bool {
     if let Some(k) = &sc.keywords {
         m.keywords = k.clone();
     }
+    if let Some(r) = &sc.regions {
+        m.regions = r.clone();
+    }
     let develop = match &sc.develop {
         Some(DevelopPatch::Full(s)) => (**s).clone(),
         Some(DevelopPatch::Partial(v)) => {

crates/engine/src/smart.rs

@@ -1,13 +1,16 @@
 //! Smart previews: a compact proxy of each photo (its decoded preview-size source, about 1 MB)
 //! kept in the library, so photos stay editable — and exportable at proxy size — while their
 //! originals are offline (an unplugged drive). The proxy is the scene-linear source scaled into
-//! 0..1 by a stored factor, sRGB-encoded and saved as a JPEG after a one-line header.
+//! 0..1 by a stored factor, sRGB-encoded and saved as a JPEG after a one-line header. The header
+//! also keeps the decoder's file-local camera tone curve (Sony ARW camera look), which is applied
+//! at render time and is not baked into the pixels.
 
 use std::path::{Path, PathBuf};
 use std::sync::Arc;
 
 use lightcraft_catalog::Photo;
 use lightcraft_color::transfer::linear_to_srgb;
+use lightcraft_pipeline::tone::CameraTone;
 use lightcraft_raster::{Rgb32f, Rgba8};
 
 const MAGIC: &[u8] = b"LCSP1\n";
@@ -18,8 +21,11 @@ pub fn file_name(p: &Photo) -> String {
     format!("{:032x}.lcsp", h.0)
 }
 
-/// Encode a source image as a smart preview.
-pub fn encode(img: &Rgb32f) -> Result<Vec<u8>, String> {
+/// The most header [`is_valid`] reads (the JSON line before the JPEG).
+const HEADER_MAX: u64 = 4096;
+
+/// Encode a source image (and the decoder's camera tone curve, if any) as a smart preview.
+pub fn encode(img: &Rgb32f, tone: Option<&CameraTone>) -> Result<Vec<u8>, String> {
     // scale so all but the brightest 0.05 % fit into 0..1
     let mut lum: Vec<f32> = img.data.iter().map(|c| c[0].max(c[1]).max(c[2])).filter(|v| v.is_finite()).collect();
     let scale = if lum.is_empty() {
@@ -47,22 +53,29 @@ pub fn encode(img: &Rgb32f) -> Result<Vec<u8>, String> {
     )
     .map_err(|e| e.to_string())?;
     let mut out = MAGIC.to_vec();
-    out.extend_from_slice(format!("{{\"w\":{},\"h\":{},\"scale\":{scale}}}\n", img.width, img.height).as_bytes());
+    let mut head = serde_json::json!({"w": img.width, "h": img.height, "scale": scale});
+    if let Some(t) = tone {
+        head["tone"] = serde_json::to_value(t).map_err(|e| e.to_string())?;
+    }
+    out.extend_from_slice(head.to_string().as_bytes());
+    out.push(b'\n');
     out.extend_from_slice(&jpg);
     Ok(out)
 }
 
-/// Decode a smart preview back into a source image.
-pub fn decode(bytes: &[u8]) -> Result<Rgb32f, String> {
+/// Decode a smart preview back into a source image and its stored camera tone curve (an invalid
+/// curve is ignored, like a missing one).
+pub fn decode(bytes: &[u8]) -> Result<(Rgb32f, Option<CameraTone>), String> {
     let rest = bytes.strip_prefix(MAGIC).ok_or("not a smart preview")?;
     let nl = rest.iter().position(|b| *b == b'\n').ok_or("bad smart preview")?;
     let head: serde_json::Value = serde_json::from_slice(&rest[..nl]).map_err(|e| e.to_string())?;
     let scale = head["scale"].as_f64().unwrap_or(1.0) as f32;
+    let tone = head.get("tone").and_then(|t| serde_json::from_value::<CameraTone>(t.clone()).ok());
     let d = lightcraft_codecs::decode(&rest[nl + 1..], Default::default()).map_err(|e| e.to_string())?;
     // the decoder undoes the sRGB encoding; the values are the source's own primaries
     let mut img = d.image;
     img.data.iter_mut().for_each(|c| *c = c.map(|v| v * scale));
-    Ok(img)
+    Ok((img, tone))
 }
 
 /// Where a library keeps its smart previews.
@@ -157,8 +170,8 @@ pub fn migrate(from: &Path, to: &Path, what: Existing) -> (usize, Vec<String>) {
 pub fn is_valid(path: &Path) -> bool {
     use std::io::{Read, Seek, SeekFrom};
     let Ok(mut f) = std::fs::File::open(path) else { return false };
-    let mut head = Vec::with_capacity(256);
-    if (&mut f).take(256).read_to_end(&mut head).is_err() {
+    let mut head = Vec::with_capacity(1024);
+    if (&mut f).take(HEADER_MAX).read_to_end(&mut head).is_err() {
         return false;
     }
     let Some(rest) = head.strip_prefix(MAGIC) else { return false };
@@ -175,9 +188,9 @@ pub fn is_valid(path: &Path) -> bool {
 }
 
 /// Load the proxy at `path`.
-pub fn load(path: &Path) -> Result<Arc<Rgb32f>, String> {
+pub fn load(path: &Path) -> Result<crate::media::DecodedSource, String> {
     let b = std::fs::read(path).map_err(|e| format!("{}: {e}", path.display()))?;
-    decode(&b).map(Arc::new)
+    decode(&b).map(|(image, camera_tone)| crate::media::DecodedSource { image: Arc::new(image), info: None, camera_tone })
 }
 
 #[cfg(test)]
@@ -228,7 +241,7 @@ mod tests {
         std::fs::create_dir_all(&a).unwrap();
         std::fs::create_dir_all(&b).unwrap();
         let img = lightcraft_scenes::demo_library()[0].render(64, 40);
-        let good = encode(&img).unwrap();
+        let good = encode(&img, None).unwrap();
         std::fs::write(a.join("1.lcsp"), &good).unwrap();
         assert!(is_valid(&a.join("1.lcsp")));
         for cut in [good.len() - 1, good.len() / 2, 10, 0] {
@@ -242,11 +255,45 @@ mod tests {
         let _ = std::fs::remove_dir_all(&base);
     }
 
+    #[test]
+    fn camera_tone_travels_with_the_proxy() {
+        let tone = CameraTone::new(std::array::from_fn(|i| {
+            let x = 0.004 * 1.17f32.powi(i as i32);
+            [x, 0.95 * (1.0 - (-2.7 * x).exp())]
+        }))
+        .unwrap();
+        let img = lightcraft_scenes::demo_library()[0].render(64, 40);
+        let bytes = encode(&img, Some(&tone)).unwrap();
+        assert_eq!(decode(&bytes).unwrap().1, Some(tone));
+        let dir = temp("tone");
+        let path = dir.join("t.lcsp");
+        std::fs::write(&path, &bytes).unwrap();
+        // the longer header is still read by the validity check, and the curve by `load`
+        assert!(is_valid(&path));
+        let loaded = load(&path).unwrap();
+        assert_eq!(loaded.camera_tone, Some(tone));
+        let header = lightcraft_pipeline::SourceInfo { raw: true, ..Default::default() };
+        assert_eq!(loaded.info_or(header).camera_tone, Some(tone));
+        // a hostile curve (reversing knots) is ignored, not trusted
+        let nl = MAGIC.len() + bytes[MAGIC.len()..].iter().position(|b| *b == b'\n').unwrap();
+        let mut head: serde_json::Value = serde_json::from_slice(&bytes[MAGIC.len()..nl]).unwrap();
+        let mut knots: Vec<[f32; 2]> = serde_json::from_value(head["tone"]["knots"].clone()).unwrap();
+        knots.swap(3, 4);
+        head["tone"]["knots"] = serde_json::json!(knots);
+        let mut hostile = MAGIC.to_vec();
+        hostile.extend_from_slice(head.to_string().as_bytes());
+        hostile.extend_from_slice(&bytes[nl..]);
+        let (pixels, tone) = decode(&hostile).unwrap();
+        assert_eq!((pixels.width, tone), (img.width, None));
+        let _ = std::fs::remove_dir_all(&dir);
+    }
+
     #[test]
     fn roundtrip_keeps_the_picture() {
         let img = lightcraft_scenes::demo_library()[0].render(160, 100);
-        let back = decode(&encode(&img).unwrap()).unwrap();
+        let (back, tone) = decode(&encode(&img, None).unwrap()).unwrap();
         assert_eq!((back.width, back.height), (img.width, img.height));
+        assert!(tone.is_none());
         let mut err = 0.0f64;
         for (a, b) in img.data.iter().zip(&back.data) {
             for k in 0..3 {

crates/engine/src/tests.rs

@@ -10,6 +10,30 @@ fn active_dev(s: &Session) -> lightcraft_develop::DevelopSettings {
     (*s.develop_of(s.active().unwrap()).unwrap()).clone()
 }
 
+#[test]
+fn changing_one_wb_control_resolves_as_shot_without_stale_tint() {
+    use lightcraft_catalog::{Photo, PhotoId, Source};
+    use lightcraft_develop::{DevelopSettings, WbMode};
+    let mut s = demo();
+    let id = PhotoId(100);
+    let mut p = Photo::new(id, Source::File { path: "synthetic.arw".into() }, "synthetic.arw", "ARW", 16, 16, "");
+    // A catalog made by the old generic-matrix Kelvin inference.
+    p.as_shot_wb = Some((6829.0, -127.0));
+    p.develop = std::sync::Arc::new(DevelopSettings::for_raw(6829.0, -127.0));
+    s.catalog.apply(lightcraft_catalog::Op::AddPhoto { photo: Box::new(p) }).unwrap();
+    s.execute("library.select", &json!({"ids": [100], "active": 100})).unwrap();
+    s.execute("develop.set", &json!({"control": "wb.temp", "value": 8000})).unwrap();
+    let d = active_dev(&s);
+    assert_eq!(d.wb.mode, WbMode::Custom);
+    assert_eq!(d.wb.temp, 8000.0);
+    assert_eq!(d.wb.tint, 0.0, "untouched tint comes from the current as-shot reference");
+    s.execute("develop.wb", &json!({"mode": "asShot"})).unwrap();
+    s.execute("develop.set", &json!({"control": "wb.tint", "value": 10})).unwrap();
+    assert_eq!(active_dev(&s).wb.temp, 6500.0);
+    s.execute("develop.reset", &json!({})).unwrap();
+    assert_eq!((active_dev(&s).wb.temp, active_dev(&s).wb.tint), (6500.0, 0.0));
+}
+
 #[test]
 fn demo_library_loads() {
     let mut s = demo();
@@ -703,3 +727,93 @@ fn curve_reset_by_channel_and_whole() {
     assert_eq!(active_dev(&s).curve, lightcraft_develop::ToneCurve::default());
     assert!(s.execute("curve.reset", &json!({"channel": "alpha"})).is_err());
 }
+
+#[test]
+fn ai_masks_without_the_model_explain_themselves() {
+    let mut s = demo();
+    let id = s.active().unwrap();
+    // an Object mask that could never be computed is refused, not left empty
+    let e = s.execute("mask.add", &json!({"kind": "object"})).unwrap_err().to_string();
+    assert!(e.contains("SAM 3") || e.contains("not available"), "{e}");
+    assert!(!e.contains("invalid parameters"), "shown as is: {e}");
+    assert!(s.develop_of(id).unwrap().masks.is_empty());
+    // an empty Object component (as an older document may hold) still takes clicks
+    let shape = lightcraft_develop::MaskShape::Object { hint: vec![], exclude: vec![], seg: None, detail: vec![], edge: 0.0 };
+    let mut d = (*s.develop_of(id).unwrap()).clone();
+    d.masks.push(lightcraft_develop::Mask {
+        id: 1,
+        components: vec![lightcraft_develop::MaskComponent { name: None, op: lightcraft_develop::MaskOp::Add, invert: false, shape }],
+        ..Default::default()
+    });
+    s.set_develop(id, d, "test").unwrap();
+    s.active_mask = Some(1);
+    // clicks and descriptions need the model: an error that says what's missing, nothing changed
+    let e = s.execute("mask.objectPoint", &json!({"x": 0.5, "y": 0.5})).unwrap_err().to_string();
+    assert!(e.contains("SAM 3") || e.contains("not available"), "{e}");
+    let e = s.execute("mask.add", &json!({"kind": "prompt", "text": "sky"})).unwrap_err().to_string();
+    assert!(e.contains("SAM 3") || e.contains("not available"), "{e}");
+    let empty = std::env::temp_dir().join(format!("lc-no-sam3-{}", std::process::id()));
+    s.segmenter.dir = Some(empty.clone());
+    let e = s.execute("mask.objectPoint", &json!({"x": 0.5, "y": 0.5})).unwrap_err().to_string();
+    assert!(e.contains(&empty.display().to_string()) || e.contains("not available"), "names the folder: {e}");
+    assert_eq!(s.develop_of(id).unwrap().masks.len(), 1);
+    // bad input is an error, not a crash
+    assert!(s.execute("mask.objectPoint", &json!({"x": 1.5, "y": 0.5})).is_err());
+    assert!(s.execute("mask.add", &json!({"kind": "prompt", "text": "  "})).is_err());
+}
+
+/// A People card's close-up is a square (in pixels) inside the photo, around the face, whatever the
+/// face rectangle says: corners, oversized and degenerate rectangles never leave the frame or panic.
+#[test]
+fn face_job_crops_a_square_inside_the_photo() {
+    use lightcraft_geom::Rect;
+    let mut s = demo();
+    let id = s.active().unwrap();
+    let (w, h) = {
+        let p = s.catalog.photo(id).unwrap();
+        (f64::from(p.width), f64::from(p.height))
+    };
+    let faces = [
+        Rect { x0: 0.40, y0: 0.30, x1: 0.50, y1: 0.45 },
+        Rect { x0: 0.0, y0: 0.0, x1: 0.05, y1: 0.05 },
+        Rect { x0: 0.95, y0: 0.95, x1: 1.0, y1: 1.0 },
+        Rect { x0: -5.0, y0: -5.0, x1: 5.0, y1: 5.0 },
+        Rect { x0: 0.5, y0: 0.5, x1: 0.5, y1: 0.5 },
+        Rect { x0: f64::NAN, y0: 0.5, x1: 0.6, y1: f64::INFINITY },
+    ];
+    for face in faces {
+        let job = s.face_job(id, face, 256).expect("a job for a photo in the library");
+        let r = job.settings.crop.geometry.rect;
+        assert!((0.0..=1.0).contains(&r.x0) && (0.0..=1.0).contains(&r.y0) && r.x1 <= 1.0 + 1e-9 && r.y1 <= 1.0 + 1e-9, "{face:?} → {r:?}");
+        assert!(r.x1 > r.x0 && r.y1 > r.y0, "{face:?} → {r:?}");
+        let (pw, ph) = ((r.x1 - r.x0) * w, (r.y1 - r.y0) * h);
+        assert!((pw - ph).abs() < 1e-6 * w.max(h), "square in pixels: {face:?} → {pw} × {ph}");
+        assert_eq!(job.settings.crop.geometry.angle, 0.0);
+    }
+    // a face around (0.45, 0.375) is centred in its crop (room to spare on every side)
+    let r = s.face_job(id, faces[0], 256).unwrap().settings.crop.geometry.rect;
+    assert!((((r.x0 + r.x1) / 2.0) - 0.45).abs() < 1e-9 && (((r.y0 + r.y1) / 2.0) - 0.375).abs() < 1e-9, "{r:?}");
+    assert!(s.face_job(lightcraft_catalog::PhotoId(u64::MAX), faces[0], 256).is_none());
+}
+
+/// Regions are on the upright photo; after Rotate Right the close-up still frames the face: the box
+/// is carried into the rotated frame the crop lives in, and the crop stays square in rotated pixels.
+#[test]
+fn face_job_follows_rotate_right() {
+    use lightcraft_geom::Rect;
+    let mut s = demo();
+    let id = s.active().unwrap();
+    let (w, h) = {
+        let p = s.catalog.photo(id).unwrap();
+        (f64::from(p.width), f64::from(p.height))
+    };
+    // a small face left of centre on the upright photo
+    let face = Rect { x0: 0.30, y0: 0.45, x1: 0.35, y1: 0.50 };
+    s.execute("photo.rotateRight", &json!({})).unwrap();
+    let r = s.face_job(id, face, 256).unwrap().settings.crop.geometry.rect;
+    // a quarter turn clockwise puts the left of the photo at the top: centre (0.325, 0.475) → (0.525, 0.325)
+    assert!((((r.x0 + r.x1) / 2.0) - 0.525).abs() < 1e-9 && (((r.y0 + r.y1) / 2.0) - 0.325).abs() < 1e-9, "{r:?}");
+    // the rotated photo is h × w pixels
+    let (pw, ph) = ((r.x1 - r.x0) * h, (r.y1 - r.y0) * w);
+    assert!((pw - ph).abs() < 1e-6 * w.max(h), "square in rotated pixels: {pw} × {ph}");
+}

crates/engine/src/tests_export.rs

@@ -323,3 +323,50 @@ fn a_failed_export_write_keeps_the_previous_file() {
     assert_ne!(std::fs::read(&prev).unwrap(), b"last week's export");
     let _ = std::fs::remove_dir_all(&dir);
 }
+
+#[cfg(unix)]
+#[test]
+fn export_protects_the_target_of_an_imported_symlink() {
+    use crate::export::{Conflict, Destination};
+    let (original_session, _, dir, src, original) = library_with_jpeg("export-symlink-original");
+    drop(original_session);
+    let alias = dir.join("alias.jpg");
+    std::os::unix::fs::symlink(&src, &alias).unwrap();
+    let sidecar = dir.join("metadata.xmp");
+    std::fs::write(&sidecar, b"<x/>").unwrap();
+    std::os::unix::fs::symlink(&sidecar, alias.with_extension("xmp")).unwrap();
+    let mut s = Session::new().with_fs();
+    s.execute("library.import", &json!({"paths": [alias.to_string_lossy()]})).unwrap();
+    let id = s.catalog.photos().next().unwrap().id;
+    s.execute("develop.set", &json!({"ids": [id.0], "control": "light.exposure", "value": 1.0})).unwrap();
+    let o = ExportOptions { conflict: Conflict::Overwrite, ..Default::default() };
+    let to = Destination { dir: String::new(), exact: Some(src.to_string_lossy().to_string()) };
+    let result = disk_batch(&mut s, id, &o, &to);
+    assert!(result.is_err(), "export replaced the original through its imported alias: {result:?}");
+    assert_eq!(std::fs::read(&src).unwrap(), original);
+    assert!(s.execute("export.checkTarget", &json!({"path": src.to_string_lossy()})).is_err());
+    assert!(s.execute("export.checkTarget", &json!({"path": sidecar.to_string_lossy()})).is_err());
+    assert_eq!(std::fs::read(&sidecar).unwrap(), b"<x/>");
+    let _ = std::fs::remove_dir_all(&dir);
+}
+
+/// Issue #134: exports can always be made again, so they are written atomically but not synced to
+/// disk file by file; an edit copy that becomes a library photo still is.
+#[test]
+fn exports_are_atomic_without_a_sync() {
+    use crate::export::{Conflict, Destination};
+    use lightcraft_catalog::safe_file::syncs_on_this_thread;
+    let (mut s, id, dir, _src, _) = library_with_jpeg("export-nosync");
+    let out = dir.join("out");
+    let to = Destination { dir: out.to_string_lossy().to_string(), exact: None };
+    let o = ExportOptions { conflict: Conflict::Unique, ..Default::default() };
+    let before = syncs_on_this_thread();
+    for _ in 0..3 {
+        disk_batch(&mut s, id, &o, &to).unwrap();
+    }
+    assert_eq!(syncs_on_this_thread(), before, "no per-file sync for exports");
+    assert_eq!(std::fs::read_dir(&out).unwrap().count(), 3, "three exports, no temp files");
+    crate::export::write_file_durable(&out.join("edit.tif").to_string_lossy(), b"tiff").unwrap();
+    assert!(syncs_on_this_thread() > before, "the durable writer syncs");
+    let _ = std::fs::remove_dir_all(&dir);
+}

crates/engine/src/tests_import.rs

@@ -144,11 +144,10 @@ fn browsing_a_folder_lists_its_photos_without_adding_them() {
     let _ = std::fs::remove_dir_all(&dir);
 }
 
-/// Issue #105: Find Missing finds renamed files by content, prefers the content match over a
-/// same-name same-size impostor, and skips (reports) photos it can't tell apart.
-#[test]
-fn find_missing_matches_renamed_files_by_content() {
-    let dir = temp_dir("missing-content");
+/// Photos a.png, b.png, c.png imported from `old`, then: a renamed into `moved`; b renamed, with
+/// an impostor (same name and size, other bytes) under its old name; c gone, with two impostors.
+fn renamed_and_ambiguous_scene(tag: &str) -> (std::path::PathBuf, Session) {
+    let dir = temp_dir(tag);
     std::fs::create_dir_all(dir.join("old")).unwrap();
     std::fs::create_dir_all(dir.join("moved/real")).unwrap();
     for (n, seed) in [("a.png", 1), ("b.png", 2), ("c.png", 3)] {
@@ -156,20 +155,26 @@ fn find_missing_matches_renamed_files_by_content() {
     }
     let mut s = Session::new().with_fs();
     s.execute("library.import", &json!({"paths": [dir.join("old").to_string_lossy()]})).unwrap();
-    // an impostor: same name and size, other bytes
     let impostor = |src: &Path, dst: &Path| {
         let mut b = std::fs::read(src).unwrap();
         let k = b.len() - 20;
         b[k] ^= 0xff;
         std::fs::write(dst, b).unwrap();
     };
-    // a: renamed; b: renamed, with an impostor under its old name; c: gone, two impostors
     std::fs::rename(dir.join("old/a.png"), dir.join("moved/Trip-001.png")).unwrap();
     impostor(&dir.join("old/b.png"), &dir.join("moved/b.png"));
     std::fs::rename(dir.join("old/b.png"), dir.join("moved/real/Trip-002.png")).unwrap();
     impostor(&dir.join("old/c.png"), &dir.join("moved/c.png"));
     impostor(&dir.join("old/c.png"), &dir.join("moved/real/c.png"));
     std::fs::remove_file(dir.join("old/c.png")).unwrap();
+    (dir, s)
+}
+
+/// Issue #105: Find Missing finds renamed files by content, prefers the content match over a
+/// same-name same-size impostor, and skips (reports) photos it can't tell apart.
+#[test]
+fn find_missing_matches_renamed_files_by_content() {
+    let (dir, mut s) = renamed_and_ambiguous_scene("missing-content");
     let r = s.execute("library.findMissing", &json!({"folder": dir.join("moved").to_string_lossy()})).unwrap();
     let found = r["found"].as_array().unwrap();
     assert_eq!(found.len(), 2, "{r}");
@@ -183,6 +188,55 @@ fn find_missing_matches_renamed_files_by_content() {
     let _ = std::fs::remove_dir_all(&dir);
 }
 
+/// Issue #104: the app plans Find Missing on a worker thread (no session) and relinks the plan
+/// afterwards; that gives exactly what the synchronous command gives — renamed files by content,
+/// impostors and look-alikes skipped (`ambiguous`).
+#[test]
+fn find_missing_planned_on_a_worker_matches_the_command() {
+    use crate::cmd::missing::{find_candidates, plan_find_missing};
+    let (dir, mut s) = renamed_and_ambiguous_scene("missing-worker");
+    let folder = dir.join("moved").to_string_lossy().to_string();
+    let candidates = find_candidates(&s.catalog);
+    let f = folder.clone();
+    let plan = std::thread::spawn(move || plan_find_missing(&candidates, &f)).join().unwrap().unwrap();
+    assert_eq!((plan.found.len(), plan.missing, plan.ambiguous.len()), (2, 1, 1), "{plan:?}");
+    let applied = s.execute("library.findMissing", &plan.to_json()).unwrap();
+    s.execute("edit.undo", &json!({})).unwrap();
+    assert_eq!(s.execute("library.missing", &json!({})).unwrap().as_array().map(Vec::len), Some(3), "undo restores all three");
+    let direct = s.execute("library.findMissing", &json!({"folder": folder})).unwrap();
+    assert_eq!(applied, direct);
+    assert_eq!(direct["found"].as_array().map(Vec::len), Some(2), "{direct}");
+    assert_eq!(direct["ambiguous"].as_array().map(Vec::len), Some(1), "{direct}");
+    let _ = std::fs::remove_dir_all(&dir);
+}
+
+/// Issue #104: a plan made on a worker is re-checked when it is applied: a photo relinked
+/// meanwhile is left alone, and a file that is now another photo's original isn't used.
+#[test]
+fn find_missing_plan_is_rechecked_when_applied() {
+    use crate::cmd::missing::{find_candidates, plan_find_missing};
+    let (dir, mut s) = renamed_and_ambiguous_scene("missing-recheck");
+    let plan = plan_find_missing(&find_candidates(&s.catalog), &dir.join("moved").to_string_lossy()).unwrap();
+    let to = |name: &str| plan.found.iter().find(|f| f.from.ends_with(name)).unwrap().clone();
+    let (a, b) = (to("a.png"), to("b.png"));
+    // meanwhile: a is relinked by hand (elsewhere), and the ambiguous c is pointed at b's file
+    std::fs::copy(&a.to, dir.join("a-elsewhere.png")).unwrap();
+    s.execute("photo.relink", &json!({"id": a.id.0, "path": dir.join("a-elsewhere.png").to_string_lossy()})).unwrap();
+    let c = plan.ambiguous[0].id;
+    s.execute("photo.relink", &json!({"id": c.0, "path": b.to})).unwrap();
+    let r = s.execute("library.findMissing", &plan.to_json()).unwrap();
+    assert_eq!(r["found"].as_array().map(Vec::len), Some(0), "{r}");
+    assert_eq!(r["ambiguous"].as_array().map(Vec::len), Some(0), "c isn't missing any more: {r}");
+    assert_eq!(r["missing"], 1, "b stays missing: its file is c's now: {r}");
+    let path_of = |id: lightcraft_catalog::PhotoId| match &s.catalog.photo(id).unwrap().source {
+        lightcraft_catalog::Source::File { path } => path.clone(),
+        _ => String::new(),
+    };
+    assert_eq!(path_of(a.id), dir.join("a-elsewhere.png").to_string_lossy());
+    assert_eq!(path_of(b.id), b.from);
+    let _ = std::fs::remove_dir_all(&dir);
+}
+
 #[test]
 fn missing_files_are_found_and_relinked() {
     let dir = std::env::temp_dir().join(format!("lc-missing-{}", std::process::id()));
@@ -425,6 +479,20 @@ fn damaged_smart_previews_are_rebuilt_and_failed_writes_leave_none() {
     let r = s.execute("library.smartPreviews", &json!({})).unwrap();
     assert_eq!((r["built"].as_u64(), r["repaired"].as_u64()), (Some(1), Some(1)), "{r}");
     assert_eq!(std::fs::read(&file).unwrap(), full, "rebuilt whole");
+    // the app's background build (issue #104) checks and repairs the same way, on a worker thread
+    std::fs::write(&file, &full[..full.len() / 2]).unwrap();
+    let r = s.execute("library.smartPreviews", &json!({"background": true})).unwrap();
+    assert_eq!(r["what"], "smart previews", "{r}");
+    let t0 = std::time::Instant::now();
+    let r = loop {
+        let r = s.execute("library.previewProgress", &json!({})).unwrap();
+        if r["running"] == false || t0.elapsed() > std::time::Duration::from_secs(60) {
+            break r;
+        }
+        std::thread::sleep(std::time::Duration::from_millis(5));
+    };
+    assert_eq!((r["done"].as_u64(), r["failed"].as_u64(), r["repaired"].as_u64()), (Some(1), Some(0), Some(1)), "{r}");
+    assert_eq!(std::fs::read(&file).unwrap(), full, "rebuilt whole in the background");
     let _ = std::fs::remove_dir_all(&src);
     let _ = std::fs::remove_dir_all(&lib);
 }

crates/engine/src/tests_import_move.rs

@@ -207,6 +207,67 @@ fn copy_import_verifies_each_copy() {
     let _ = std::fs::remove_dir_all(&base);
 }
 
+/// Copy verifies against the probe's content hash (issue #134): the hash, not a re-read of the
+/// source, is the reference — a copy that matches the source but not the hash is refused, a
+/// corrupted copy is caught, and the file hash agrees with `hash_bytes` across read chunks.
+#[test]
+fn copy_is_verified_against_the_probe_hash() {
+    use crate::import_move::copy_verified;
+    let base = temp_dir("copyhash");
+    let src = base.join("src.bin");
+    // larger than one 1 MB read, not a multiple of it
+    let bytes: Vec<u8> = (0..(3 << 20) + 12_345u32).map(|i| (i.wrapping_mul(2_654_435_761) >> 13) as u8).collect();
+    std::fs::write(&src, &bytes).unwrap();
+    let good = lightcraft_preview::hash_bytes(&bytes);
+    copy_verified(&src, &base.join("ok.bin"), Some(good)).unwrap();
+    assert_eq!(std::fs::read(base.join("ok.bin")).unwrap(), bytes);
+    // a hash that doesn't match: refused (a byte compare with the source would have passed)
+    let stale = lightcraft_preview::hash_bytes(b"what the probe read earlier");
+    let e = copy_verified(&src, &base.join("stale.bin"), Some(stale)).unwrap_err();
+    assert!(e.to_string().contains("differs"), "{e}");
+    assert!(!base.join("stale.bin").exists(), "the refused copy is removed");
+    // a copy that comes out different: caught by the hash
+    inject(Fault::Corrupt);
+    let r = copy_verified(&src, &base.join("bad.bin"), Some(good));
+    inject(Fault::None);
+    assert!(r.is_err());
+    assert!(!base.join("bad.bin").exists());
+    assert_eq!(std::fs::read(&src).unwrap(), bytes, "the source is untouched");
+    let _ = std::fs::remove_dir_all(&base);
+}
+
+/// A file replaced after Review Import probed it is not imported on the strength of the old probe:
+/// its copy no longer matches the probe's hash, so it's reported as failed and nothing is left.
+#[test]
+fn copy_import_refuses_a_file_changed_since_the_review() {
+    let base = temp_dir("copychanged");
+    let (card, dest) = (base.join("card"), base.join("out"));
+    write_png(&card.join("a.png"), 3);
+    let mut s = session();
+    let r = s.execute("library.importPreview", &json!({"paths": [card.to_string_lossy()]})).unwrap();
+    assert_eq!(r["scanned"], 1, "{r}");
+    write_png(&card.join("a.png"), 9); // other pixels
+    let r = s
+        .execute(
+            "library.import",
+            &json!({"paths": [card.to_string_lossy()], "mode": "copy", "destination": dest.to_string_lossy(), "organize": "flat"}),
+        )
+        .unwrap();
+    assert_eq!(len(&r, "imported"), 0, "{r}");
+    assert_eq!(len(&r, "failed"), 1, "{r}");
+    assert!(r.to_string().contains("changed meanwhile"), "{r}");
+    assert_eq!(files_under(&dest), Vec::<String>::new());
+    // importing again probes afresh and succeeds
+    let r = s
+        .execute(
+            "library.import",
+            &json!({"paths": [card.to_string_lossy()], "mode": "copy", "destination": dest.to_string_lossy(), "organize": "flat"}),
+        )
+        .unwrap();
+    assert_eq!(len(&r, "imported"), 1, "{r}");
+    let _ = std::fs::remove_dir_all(&base);
+}
+
 /// A source that can't be removed (a read-only card) stays and is reported; the photo is
 /// imported from its copy.
 #[test]
@@ -320,3 +381,55 @@ fn move_into_the_library_is_saved_before_sources_go() {
     assert_eq!(photo_paths(&again), [want.to_string_lossy()]);
     let _ = std::fs::remove_dir_all(&base);
 }
+
+/// Timing for issue #134 (not a pass/fail test): `cargo test -p lightcraft-engine --release
+/// write_policy_timing -- --ignored --nocapture`. Writes N export-sized files durably (temp +
+/// sync + rename) and atomically only, and copies N files verified byte for byte and against the
+/// probe hash, alternating so a loaded machine affects both alike. `LIGHTCRAFT_BENCH_DIR` puts
+/// the files on another volume (a USB drive or a NAS is where the difference shows).
+#[test]
+#[ignore]
+fn write_policy_timing() {
+    use crate::import_move::copy_verified;
+    use lightcraft_catalog::safe_file::{write_atomic, write_atomic_nosync};
+    use std::time::{Duration, Instant};
+    let root = std::env::var_os("LIGHTCRAFT_BENCH_DIR").map(PathBuf::from).unwrap_or_else(std::env::temp_dir);
+    let base = root.join(format!("lc-write-policy-{}", std::process::id()));
+    let _ = std::fs::remove_dir_all(&base);
+    std::fs::create_dir_all(&base).unwrap();
+    let data = |n: usize, seed: u32| -> Vec<u8> { (0..n as u32).map(|i| (i.wrapping_add(seed).wrapping_mul(2_654_435_761) >> 11) as u8).collect() };
+    let (n, size) = (200usize, 300 << 10);
+    let (mut synced, mut unsynced) = (Duration::ZERO, Duration::ZERO);
+    for i in 0..n {
+        let b = data(size, i as u32);
+        let t = Instant::now();
+        write_atomic(&base.join(format!("sync-{i}.jpg")), &b).unwrap();
+        synced += t.elapsed();
+        let t = Instant::now();
+        write_atomic_nosync(&base.join(format!("nosync-{i}.jpg")), &b).unwrap();
+        unsynced += t.elapsed();
+    }
+    println!("export {n} × {} KB: write_atomic (synced) {synced:?}, write_atomic_nosync {unsynced:?}", size >> 10);
+    let (n, size) = (40usize, 8 << 20);
+    let card = base.join("card");
+    std::fs::create_dir_all(&card).unwrap();
+    let hashes: Vec<_> = (0..n)
+        .map(|i| {
+            let b = data(size, 7 * i as u32);
+            std::fs::write(card.join(format!("{i}.raw")), &b).unwrap();
+            lightcraft_preview::hash_bytes(&b)
+        })
+        .collect();
+    let (mut bytewise, mut hashed) = (Duration::ZERO, Duration::ZERO);
+    for (i, h) in hashes.iter().enumerate() {
+        let src = card.join(format!("{i}.raw"));
+        let t = Instant::now();
+        copy_verified(&src, &base.join(format!("bytes-{i}.raw")), None).unwrap();
+        bytewise += t.elapsed();
+        let t = Instant::now();
+        copy_verified(&src, &base.join(format!("hash-{i}.raw")), Some(*h)).unwrap();
+        hashed += t.elapsed();
+    }
+    println!("copy {n} × {} MB: byte compare with the source {bytewise:?}, probe hash {hashed:?}", size >> 20);
+    let _ = std::fs::remove_dir_all(&base);
+}

crates/engine/src/tests_organize.rs

@@ -201,6 +201,25 @@ fn album_source_reports_in_library_state_and_persists_the_view() {
     let _ = std::fs::remove_dir_all(&dir);
 }
 
+/// A library opens unfiltered: the source and sort come back, a filter from the last session does not
+/// (it would hide photos behind a small badge).
+#[test]
+fn filters_are_not_restored_when_a_library_reopens() {
+    let dir = temp_dir("filter-not-restored");
+    let mut s = open(&dir);
+    let all = s.visible_cloned().len();
+    s.execute("library.sort", &json!({"key": "fileName"})).unwrap();
+    s.execute("library.filter", &json!({"rating": 5, "date": "2026-01-16", "person": "Jane Doe"})).unwrap();
+    assert!(s.visible_cloned().len() < all);
+    s.close_library().unwrap();
+    drop(s);
+    let mut s2 = open(&dir);
+    assert_eq!(s2.filter, lightcraft_catalog::Filter::default());
+    assert_eq!(s2.visible_cloned().len(), all);
+    assert_eq!(serde_json::to_value(s2.sort).unwrap()["key"], "fileName", "the rest of the view is restored");
+    let _ = std::fs::remove_dir_all(&dir);
+}
+
 #[test]
 fn filter_chips_clear_one_filter_and_total_ignores_the_filter() {
     let dir = temp_dir("chips");

crates/engine/src/tests_segment.rs

@@ -0,0 +1,232 @@
+//! AI masks without the SAM 3 model (it is never required): every request is a clear error that
+//! comes back at once, nothing waits on the network or the model, a damaged model is an error
+//! (not a crash or a stuck "busy"), and the download command needs consent and fails cleanly.
+//! No test touches the internet: downloads go to a local server.
+
+use std::time::{Duration, Instant};
+
+use serde_json::json;
+
+use crate::Session;
+use crate::segment::{NOT_INSTALLED, Segmenter};
+
+fn tmp(name: &str) -> std::path::PathBuf {
+    let d = std::env::temp_dir().join(format!("lc-sam3-engine-{name}-{}", std::process::id()));
+    let _ = std::fs::remove_dir_all(&d);
+    d
+}
+
+/// A folder that looks installed but holds no usable model.
+fn damaged_model(name: &str) -> std::path::PathBuf {
+    let d = tmp(name);
+    std::fs::create_dir_all(&d).unwrap();
+    std::fs::write(d.join("model.safetensors"), b"\x10\x00\x00\x00\x00\x00\x00\x00{not json at all}").unwrap();
+    std::fs::write(d.join("vocab.json"), b"{}").unwrap();
+    std::fs::write(d.join("merges.txt"), b"#version: 0.2\n").unwrap();
+    d
+}
+
+/// Poll until the worker is idle (or `limit` passes), collecting messages.
+fn settle(s: &mut Session, limit: Duration) -> Vec<String> {
+    let t = Instant::now();
+    let mut messages = Vec::new();
+    loop {
+        let p = s.segment_poll();
+        messages.extend(p.messages);
+        if !s.segmenter.busy() && !s.segmenter.detail_busy() {
+            messages.extend(s.segment_poll().messages);
+            return messages;
+        }
+        assert!(t.elapsed() < limit, "the worker never finished");
+        std::thread::sleep(Duration::from_millis(10));
+    }
+}
+
+#[test]
+fn status_and_model_commands_without_the_model() {
+    let mut s = Session::with_demo();
+    let st = s.execute("segment.model.status", &json!({})).unwrap();
+    assert_eq!(st["available"], Segmenter::AVAILABLE);
+    assert_eq!(st["installed"], false);
+    assert_eq!(st["download"]["running"], false);
+    assert!(st["license"].as_str().unwrap().contains("SAM License"));
+    // downloading needs the user's consent, and names the size and the licence
+    let e = s.execute("segment.model.download", &json!({})).unwrap_err().to_string();
+    assert!(e.contains("acknowledged") && e.contains("SAM License") && e.contains("GB"), "{e}");
+    let e = s.execute("segment.model.download", &json!({"acknowledged": "yes"})).unwrap_err().to_string();
+    assert!(e.contains("acknowledged"), "{e}");
+    assert_eq!(s.execute("segment.model.cancel", &json!({})).unwrap()["cancelled"], false);
+    if !Segmenter::AVAILABLE {
+        assert!(s.execute("segment.model.download", &json!({"acknowledged": true})).is_err());
+        return;
+    }
+    // no folder, then no download location: clear errors, nothing started
+    let e = s.execute("segment.model.download", &json!({"acknowledged": true})).unwrap_err().to_string();
+    assert!(e.contains("no folder"), "{e}");
+    let dir = tmp("nomirrors");
+    s.segmenter.dir = Some(dir.clone());
+    s.segmenter.mirrors_file = Some(dir.join("none.txt"));
+    if s.segmenter.mirrors().is_empty() {
+        let e = s.execute("segment.model.download", &json!({"acknowledged": true})).unwrap_err().to_string();
+        assert!(e.contains("LIGHTCRAFT_SAM3_MIRRORS"), "{e}");
+    }
+    assert!(!s.segmenter.download_status().running);
+}
+
+#[cfg(feature = "sam")]
+#[test]
+fn a_failing_download_ends_with_an_error_and_never_blocks() {
+    use std::io::{BufRead, BufReader, Write};
+    // a local mirror that has nothing
+    let l = std::net::TcpListener::bind("127.0.0.1:0").unwrap();
+    let base = format!("http://{}/sam3", l.local_addr().unwrap());
+    std::thread::spawn(move || {
+        for mut c in l.incoming().flatten() {
+            let mut r = BufReader::new(c.try_clone().unwrap());
+            let mut line = String::new();
+            while r.read_line(&mut line).unwrap_or(0) > 2 {
+                line.clear();
+            }
+            let _ = c.write_all(b"HTTP/1.1 404 Not Found\r\nContent-Length: 13\r\nConnection: close\r\n\r\n<h1>404</h1>\n");
+        }
+    });
+    let dir = tmp("download404");
+    let mirrors = dir.with_extension("mirrors.txt");
+    std::fs::write(&mirrors, format!("# test mirror\n{base}\n")).unwrap();
+    let mut s = Session::with_demo();
+    s.segmenter.dir = Some(dir.clone());
+    s.segmenter.mirrors_file = Some(mirrors.clone());
+    let t = Instant::now();
+    let r = s.execute("segment.model.download", &json!({"acknowledged": true})).unwrap();
+    assert_eq!(r["started"], true);
+    assert!(t.elapsed() < Duration::from_secs(1), "starting a download returns at once");
+    // a second request while it runs starts nothing
+    let again = s.execute("segment.model.download", &json!({"acknowledged": true})).unwrap();
+    assert!(again["started"] == false || again["downloading"] == false);
+    let t = Instant::now();
+    while s.segmenter.download_status().running {
+        assert!(t.elapsed() < Duration::from_secs(30), "the download never ended");
+        // AI mask requests meanwhile: an error at once, never a wait
+        let q = Instant::now();
+        let e = s.execute("mask.add", &json!({"kind": "prompt", "text": "sky"})).unwrap_err().to_string();
+        assert!(e.contains(NOT_INSTALLED), "{e}");
+        assert!(q.elapsed() < Duration::from_millis(500));
+        std::thread::sleep(Duration::from_millis(20));
+    }
+    let st = s.segmenter.download_status();
+    assert!(!st.finished);
+    let e = st.error.unwrap();
+    assert!(e.contains("not found"), "{e}");
+    assert!(!s.segmenter.installed());
+    // nothing was left behind under a real name, and no error page was saved
+    for f in ["model.safetensors", "vocab.json", "merges.txt", "vocab.json.part"] {
+        assert!(!dir.join(f).exists(), "{f}");
+    }
+    let _ = std::fs::remove_dir_all(&dir);
+    let _ = std::fs::remove_file(&mirrors);
+}
+
+/// The app (background mode) never waits: with the model missing every request fails at once;
+/// with a damaged model the requests are queued, fail on the worker, and come back as messages.
+#[test]
+fn background_requests_never_wait_and_failures_come_back_as_messages() {
+    let mut s = Session::with_demo();
+    s.segmenter.background = true;
+    let id = s.active().unwrap();
+    s.segmenter.dir = Some(tmp("missing"));
+    for (cmd, p) in [("mask.add", json!({"kind": "object"})), ("mask.add", json!({"kind": "prompt", "text": "sky"})), ("segment.prepare", json!({}))]
+    {
+        let t = Instant::now();
+        let e = s.execute(cmd, &p).unwrap_err().to_string();
+        assert!(t.elapsed() < Duration::from_millis(500), "{cmd}");
+        if Segmenter::AVAILABLE {
+            assert!(e.starts_with(NOT_INSTALLED), "{cmd}: {e}");
+        } else {
+            assert!(e.contains("not available"), "{cmd}: {e}");
+        }
+    }
+    assert!(s.develop_of(id).unwrap().masks.is_empty());
+    if !Segmenter::AVAILABLE {
+        return;
+    }
+    // a model folder whose weights are damaged
+    let dir = damaged_model("damaged");
+    s.segmenter.dir = Some(dir.clone());
+    assert!(s.segmenter.installed());
+    let t = Instant::now();
+    s.execute("mask.add", &json!({"kind": "object"})).unwrap();
+    let r = s.execute("mask.objectPoint", &json!({"x": 0.5, "y": 0.5})).unwrap();
+    assert_eq!(r["pending"], true);
+    assert!(s.segmenter.pending_clicks().is_some_and(|p| p.hint.len() == 1));
+    // a second click while the first is on its way builds on it
+    let r = s.execute("mask.objectPoint", &json!({"x": 0.6, "y": 0.5, "exclude": true})).unwrap();
+    assert_eq!((r["include"].as_u64(), r["exclude"].as_u64()), (Some(1), Some(1)));
+    let r = s.execute("mask.add", &json!({"kind": "prompt", "text": "the sky"})).unwrap();
+    assert_eq!(r["pending"], true);
+    assert!(t.elapsed() < Duration::from_secs(1), "nothing waited for the model: {:?}", t.elapsed());
+    let messages = settle(&mut s, Duration::from_secs(60));
+    assert!(!messages.is_empty() && messages.iter().all(|m| !m.is_empty()), "{messages:?}");
+    assert!(messages.iter().any(|m| m.contains("model.safetensors") || m.contains("SAM 3")), "{messages:?}");
+    assert!(s.segmenter.pending_clicks().is_none());
+    // the Object mask is there, without a selection; no Describe mask was made from nothing
+    let d = s.develop_of(id).unwrap();
+    assert_eq!(d.masks.len(), 1);
+    assert!(matches!(&d.masks[0].components[0].shape, lightcraft_develop::MaskShape::Object { seg: None, .. }));
+    assert!(!s.segmenter.busy() && !s.segmenter.loaded());
+    let _ = std::fs::remove_dir_all(&dir);
+}
+
+/// CLI / MCP (waiting mode): a damaged model is an error from the command, quickly.
+#[test]
+fn waiting_requests_with_a_damaged_model_are_errors() {
+    if !Segmenter::AVAILABLE {
+        return;
+    }
+    let mut s = Session::with_demo();
+    let id = s.active().unwrap();
+    let dir = damaged_model("damaged-wait");
+    s.segmenter.dir = Some(dir.clone());
+    let e = s.execute("mask.add", &json!({"kind": "prompt", "text": "sky"})).unwrap_err().to_string();
+    assert!(e.contains("model.safetensors") || e.contains("SAM 3"), "{e}");
+    let e = s.execute("mask.add", &json!({"kind": "object", "points": [[0.5, 0.5]]})).unwrap_err().to_string();
+    assert!(!e.is_empty());
+    assert!(s.develop_of(id).unwrap().masks.is_empty());
+    assert!(!s.segmenter.busy());
+    // a stored segmentation needs no model at all (replayed or pasted masks)
+    let seg = serde_json::to_value(lightcraft_develop::SegMask::from_logits(4, &[5.0; 16])).unwrap();
+    s.segmenter.dir = None;
+    s.execute("mask.add", &json!({"kind": "prompt", "text": "sky", "seg": seg})).unwrap();
+    assert_eq!(s.develop_of(id).unwrap().masks.len(), 1);
+    let _ = std::fs::remove_dir_all(&dir);
+}
+
+/// Too many clicks on one Object selection are refused, not sent to the model.
+#[test]
+fn object_clicks_are_capped() {
+    if !Segmenter::AVAILABLE {
+        return;
+    }
+    let mut s = Session::with_demo();
+    s.segmenter.background = true;
+    let dir = damaged_model("clicks");
+    s.segmenter.dir = Some(dir.clone());
+    let id = s.active().unwrap();
+    let mut d = (*s.develop_of(id).unwrap()).clone();
+    let many = vec![lightcraft_geom::Point::new(0.5, 0.5); crate::segment::MAX_CLICKS];
+    d.masks.push(lightcraft_develop::Mask {
+        id: 1,
+        components: vec![lightcraft_develop::MaskComponent {
+            name: None,
+            op: lightcraft_develop::MaskOp::Add,
+            invert: false,
+            shape: lightcraft_develop::MaskShape::Object { hint: many, exclude: vec![], seg: None, detail: vec![], edge: 0.0 },
+        }],
+        ..Default::default()
+    });
+    s.set_develop(id, d, "test").unwrap();
+    s.active_mask = Some(1);
+    let e = s.execute("mask.objectPoint", &json!({"x": 0.5, "y": 0.5})).unwrap_err().to_string();
+    assert!(e.contains("at most"), "{e}");
+    assert!(!s.segmenter.busy());
+    let _ = std::fs::remove_dir_all(&dir);
+}

crates/engine/src/tests_xmp.rs

@@ -173,6 +173,162 @@ fn foreign_crs_sidecar_on_import_and_read_from_file() {
     let _ = std::fs::remove_dir_all(&src);
 }
 
+const MWG_REGIONS: &str = r#"<?xpacket begin="" id="W5M0MpCehiHzreSzNTczkc9d"?>
+<x:xmpmeta xmlns:x="adobe:ns:meta/">
+ <rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#">
+  <rdf:Description rdf:about=""
+    xmlns:mwg-rs="http://www.metadataworkinggroup.com/schemas/regions/"
+    xmlns:stArea="http://ns.adobe.com/xmp/sType/Area#"
+    xmlns:stDim="http://ns.adobe.com/xap/1.0/sType/Dimensions#">
+   <mwg-rs:Regions>
+    <rdf:Description>
+     <mwg-rs:AppliedToDimensions stDim:w="100" stDim:h="100" stDim:unit="pixel"/>
+     <mwg-rs:RegionList>
+      <rdf:Bag>
+       <rdf:li>
+        <rdf:Description mwg-rs:Name="Jane Doe" mwg-rs:Type="Face">
+         <mwg-rs:Area stArea:x="0.5" stArea:y="0.5" stArea:w="0.3" stArea:h="0.4" stArea:unit="normalized"/>
+        </rdf:Description>
+       </rdf:li>
+      </rdf:Bag>
+     </mwg-rs:RegionList>
+    </rdf:Description>
+   </mwg-rs:Regions>
+  </rdf:Description>
+ </rdf:RDF>
+</x:xmpmeta>
+<?xpacket end="w"?>"#;
+
+/// A face region written by Lightroom (MWG-RS) into a sidecar reaches `Photo.meta.regions` on
+/// import — the same path real catalogs use, exercised end to end rather than just at the parser.
+#[test]
+fn regions_from_sidecar_are_read_on_import() {
+    let src = temp_dir("regions");
+    write_png(&src.join("portrait.png"), 9);
+    std::fs::write(src.join("portrait.xmp"), MWG_REGIONS).unwrap();
+    let mut s = Session::new().with_fs();
+    let r = s.execute("library.import", &json!({"paths": [src.to_string_lossy()]})).unwrap();
+    assert_eq!(r["sidecars"], 1);
+    let p = s.catalog.photos().next().unwrap().clone();
+    assert_eq!(p.meta.regions.len(), 1);
+    let region = &p.meta.regions[0];
+    assert_eq!(region.name.as_deref(), Some("Jane Doe"));
+    assert_eq!(region.kind, lightcraft_meta::RegionKind::Face);
+    assert!((region.rect.width() - 0.3).abs() < 1e-9, "{:?}", region.rect);
+    let _ = std::fs::remove_dir_all(&src);
+}
+
+/// Removing a face box is a catalog-only, undoable edit: it never rewrites the sidecar (Lightroom's
+/// regions and everything else in it stay byte for byte), even with auto-write on.
+#[test]
+fn removing_a_region_is_undoable_and_leaves_the_sidecar_alone() {
+    let src = temp_dir("region-remove");
+    write_png(&src.join("portrait.png"), 9);
+    std::fs::write(src.join("portrait.xmp"), MWG_REGIONS).unwrap();
+    let mut s = Session::new().with_fs();
+    s.execute("library.import", &json!({"paths": [src.to_string_lossy()]})).unwrap();
+    let id = s.active().unwrap();
+    s.execute("library.xmpPreferences", &json!({"autoWrite": true})).unwrap();
+    let before = std::fs::read(src.join("portrait.xmp")).unwrap();
+    let n = s.catalog.photo(id).unwrap().meta.regions.len();
+    assert!(n >= 1);
+    assert!(s.execute("photo.removeRegion", &json!({"index": n})).is_err(), "out of range");
+    assert!(s.execute("photo.removeRegion", &json!({})).is_err(), "no index");
+    let r = s.execute("photo.removeRegion", &json!({"index": 0})).unwrap();
+    assert_eq!(r["removed"], "Jane Doe");
+    assert_eq!(s.catalog.photo(id).unwrap().meta.regions.len(), n - 1);
+    assert_eq!(std::fs::read(src.join("portrait.xmp")).unwrap(), before, "the sidecar is untouched");
+    // an ordinary edit still auto-writes (the guard is per command)
+    s.execute("photo.rate", &json!({"rating": 4})).unwrap();
+    assert_ne!(std::fs::read(src.join("portrait.xmp")).unwrap(), before, "auto-write still works for other edits");
+    // undo brings the region back
+    s.execute("edit.undo", &json!({})).unwrap();
+    s.execute("edit.undo", &json!({})).unwrap();
+    assert_eq!(s.catalog.photo(id).unwrap().meta.regions.len(), n);
+    let _ = std::fs::remove_dir_all(&src);
+}
+
+/// Resizing a face box is a catalog-only, undoable edit with strict input handling; it leaves the
+/// sidecar alone like removal does.
+#[test]
+fn resizing_a_region_validates_clamps_undoes_and_leaves_the_sidecar_alone() {
+    let src = temp_dir("region-resize");
+    write_png(&src.join("portrait.png"), 9);
+    std::fs::write(src.join("portrait.xmp"), MWG_REGIONS).unwrap();
+    let mut s = Session::new().with_fs();
+    s.execute("library.import", &json!({"paths": [src.to_string_lossy()]})).unwrap();
+    let id = s.active().unwrap();
+    s.execute("library.xmpPreferences", &json!({"autoWrite": true})).unwrap();
+    let before = std::fs::read(src.join("portrait.xmp")).unwrap();
+    let original = s.catalog.photo(id).unwrap().meta.regions[0].rect;
+    let set = |s: &mut Session, rect: serde_json::Value| s.execute("photo.setRegion", &json!({"index": 0, "rect": rect}));
+    // hostile input is an error and changes nothing
+    for bad in [
+        json!({"x0": 0.1, "y0": 0.1, "x1": 0.1, "y1": 0.5}),
+        json!({"x0": 0.1, "y0": 0.1, "x1": 0.1001, "y1": 0.5}),
+        json!({"x0": 0.1, "y0": 0.1, "x1": 0.5}),
+        json!({"x0": "a", "y0": 0.1, "x1": 0.5, "y1": 0.5}),
+        json!({"x0": null, "y0": 0.1, "x1": 0.5, "y1": 0.5}),
+    ] {
+        assert!(set(&mut s, bad.clone()).is_err(), "{bad}");
+    }
+    assert!(s.execute("photo.setRegion", &json!({"index": 9, "rect": {"x0": 0.1, "y0": 0.1, "x1": 0.5, "y1": 0.5}})).is_err(), "no such region");
+    assert!(s.execute("photo.setRegion", &json!({"index": 0})).is_err(), "no rect");
+    assert_eq!(s.catalog.photo(id).unwrap().meta.regions[0].rect, original);
+    // corners given in any order and outside the photo are clamped into it
+    let r = set(&mut s, json!({"x0": 0.6, "y0": 1.5, "x1": -0.2, "y1": 0.2})).unwrap();
+    assert_eq!(r["rect"], json!({"x0": 0.0, "y0": 0.2, "x1": 0.6, "y1": 1.0}));
+    let now = s.catalog.photo(id).unwrap().meta.regions[0].rect;
+    assert_eq!((now.x0, now.y0, now.x1, now.y1), (0.0, 0.2, 0.6, 1.0));
+    assert_eq!(std::fs::read(src.join("portrait.xmp")).unwrap(), before, "the sidecar is untouched");
+    s.execute("edit.undo", &json!({})).unwrap();
+    assert_eq!(s.catalog.photo(id).unwrap().meta.regions[0].rect, original);
+    let _ = std::fs::remove_dir_all(&src);
+}
+
+/// Re-reading a sidecar: one that has `mwg-rs:Regions` is authoritative, so an emptied region list
+/// clears the stale regions; one without `mwg-rs:Regions` (an app that doesn't do regions) leaves the
+/// photo's regions alone.
+#[test]
+fn rereading_a_sidecar_clears_regions_only_when_it_states_them() {
+    let src = temp_dir("region-reread");
+    write_png(&src.join("portrait.png"), 9);
+    std::fs::write(src.join("portrait.xmp"), MWG_REGIONS).unwrap();
+    let mut s = Session::new().with_fs();
+    s.execute("library.import", &json!({"paths": [src.to_string_lossy()]})).unwrap();
+    let id = s.active().unwrap();
+    assert_eq!(s.catalog.photo(id).unwrap().meta.regions.len(), 1);
+    // another app rewrote the sidecar without any notion of regions: they stay
+    std::fs::write(
+        src.join("portrait.xmp"),
+        r#"<x:xmpmeta xmlns:x="adobe:ns:meta/"><rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#">
+  <rdf:Description rdf:about="" xmlns:xmp="http://ns.adobe.com/xap/1.0/" xmp:Rating="3"/>
+</rdf:RDF></x:xmpmeta>"#,
+    )
+    .unwrap();
+    s.execute("photo.readMetadataFromFile", &json!({})).unwrap();
+    let p = s.catalog.photo(id).unwrap();
+    assert_eq!(p.rating, 3, "the sidecar was read");
+    assert_eq!(p.meta.regions.len(), 1, "a sidecar without mwg-rs:Regions keeps the photo's regions");
+    // a region-aware app removed every region: the sidecar says so, and the catalog follows
+    let emptied = MWG_REGIONS.replace(
+        r#"<rdf:li>
+        <rdf:Description mwg-rs:Name="Jane Doe" mwg-rs:Type="Face">
+         <mwg-rs:Area stArea:x="0.5" stArea:y="0.5" stArea:w="0.3" stArea:h="0.4" stArea:unit="normalized"/>
+        </rdf:Description>
+       </rdf:li>"#,
+        "",
+    );
+    assert_ne!(emptied, MWG_REGIONS);
+    std::fs::write(src.join("portrait.xmp"), emptied).unwrap();
+    s.execute("photo.readMetadataFromFile", &json!({})).unwrap();
+    assert!(s.catalog.photo(id).unwrap().meta.regions.is_empty(), "an emptied region list clears stale regions");
+    // undo brings them back
+    s.execute("edit.undo", &json!({})).unwrap();
+    assert_eq!(s.catalog.photo(id).unwrap().meta.regions.len(), 1);
+    let _ = std::fs::remove_dir_all(&src);
+}
+
 fn synthetic_dng(xmp: &str) -> Vec<u8> {
     synthetic_dng_with(Some(xmp), lightcraft_meta::Metadata::default())
 }

crates/engine/src/view.rs

@@ -163,7 +163,9 @@ pub fn filter_chips(f: &Filter, cat: &Catalog) -> Vec<FilterChip> {
     if let Some(e) = f.edited {
         add(if e { "Edited".into() } else { "Unedited".into() }, json!({"edited": Null}));
     }
-    for (name, key, val) in [("Camera", "camera", &f.camera), ("Lens", "lens", &f.lens), ("Keyword", "keyword", &f.keyword)] {
+    for (name, key, val) in
+        [("Camera", "camera", &f.camera), ("Lens", "lens", &f.lens), ("Keyword", "keyword", &f.keyword), ("Person", "person", &f.person)]
+    {
         if let Some(x) = val {
             add(format!("{name}: {x}"), json!({key: Null}));
         }

crates/geom/src/lib.rs

@@ -332,6 +332,23 @@ impl Orientation {
         // flipH ∘ rot(t) = rot(-t) ∘ flipH
         Orientation::from_parts(!f, (4 - t) % 4)
     }
+    /// The orientation that undoes this one (`o.inverse().map(o.map(p)) == p`). Flips and half turns
+    /// are their own inverses; quarter turns swap.
+    pub fn inverse(self) -> Orientation {
+        match self {
+            Orientation::Rotate90 => Orientation::Rotate270,
+            Orientation::Rotate270 => Orientation::Rotate90,
+            o => o,
+        }
+    }
+    /// Map a rectangle in normalized (0..1) coordinates of the stored image to normalized coordinates
+    /// of the oriented one (e.g. a face region given on the upright photo → the frame after the user's
+    /// Rotate Left/Right).
+    pub fn map_norm_rect(self, r: Rect) -> Rect {
+        let (ax, ay) = self.map(r.x0, r.y0, 1.0, 1.0);
+        let (bx, by) = self.map(r.x1, r.y1, 1.0, 1.0);
+        Rect::from_points(Point::new(ax, ay), Point::new(bx, by))
+    }
     /// Map a point in stored pixel space (w×h stored dims) to oriented space.
     pub fn map(self, x: f64, y: f64, w: f64, h: f64) -> (f64, f64) {
         let (flip, t) = self.to_parts();
@@ -417,6 +434,19 @@ mod tests {
         assert_eq!(Orientation::Rotate90.flipped_h().flipped_h(), Orientation::Rotate90);
     }
 
+    #[test]
+    fn orientation_inverse_and_norm_rect() {
+        let r = Rect::new(0.1, 0.2, 0.3, 0.6);
+        for v in 1..=8 {
+            let o = Orientation::from_exif(v);
+            let back = o.inverse().map_norm_rect(o.map_norm_rect(r));
+            assert!([back.x0 - r.x0, back.y0 - r.y0, back.x1 - r.x1, back.y1 - r.y1].iter().all(|d| d.abs() < 1e-12), "{o:?}: {back:?}");
+        }
+        // a quarter turn clockwise: the left of the upright photo becomes its top
+        let q = Orientation::Rotate90.map_norm_rect(r);
+        assert!([q.x0 - 0.4, q.y0 - 0.1, q.x1 - 0.8, q.y1 - 0.3].iter().all(|d| d.abs() < 1e-12), "{q:?}");
+    }
+
     proptest::proptest! {
         #[test]
         fn affine_inverse_prop(a in -3.0f64..3.0, sx in 0.1f64..5.0, sy in 0.1f64..5.0, tx in -50.0f64..50.0, px in -20.0f64..20.0, py in -20.0f64..20.0) {

crates/gpu/src/backend.rs

@@ -0,0 +1,234 @@
+//! Which wgpu backends LightCraft lets wgpu use — for its compute device and for the desktop
+//! window (eframe) — and the crash sentinel around device creation (issue #136).
+//!
+//! wgpu loads the system driver of *every* backend in the instance's set while it enumerates
+//! adapters, even when it then picks another one: with Vulkan in the set, a broken Vulkan driver
+//! can crash the process (an access violation inside the driver DLL, which nothing can catch)
+//! although DX12 would have been used. So Windows defaults to DX12 alone. macOS uses Metal, Linux
+//! Vulkan (plus GL for the window when the build has it).
+//!
+//! Overrides, read once per process:
+//! - `LIGHTCRAFT_GPU_BACKEND` = `dx12` | `vulkan` | `metal` | `gl` (comma lists allowed), `auto`
+//!   (the platform default), or `off` (no GPU compute; the window still needs one backend and
+//!   keeps the platform default);
+//! - else `WGPU_BACKEND` (wgpu's own variable, same names) for both the window and compute.
+//!
+//! Backends this build doesn't contain (e.g. `gl`: the GL backend isn't compiled in) are ignored
+//! with a warning and the platform default is used.
+
+use std::path::PathBuf;
+use std::sync::Mutex;
+
+pub use wgpu::Backends;
+
+/// What the environment asks for.
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub enum BackendChoice {
+    /// The platform default.
+    Auto,
+    /// No GPU compute.
+    Off,
+    /// These backends.
+    Use(Backends),
+}
+
+/// Parse a backend list (`"dx12"`, `"vulkan,gl"`, `"auto"`, `"off"`…). `None`: nothing usable in
+/// it (empty or unknown names).
+pub fn parse_backends(s: &str) -> Option<BackendChoice> {
+    let s = s.trim().to_ascii_lowercase();
+    match s.as_str() {
+        "" => None,
+        "auto" | "default" => Some(BackendChoice::Auto),
+        "off" | "none" | "cpu" | "0" | "false" | "no" => Some(BackendChoice::Off),
+        _ => {
+            let b = Backends::from_comma_list(&s);
+            (!b.is_empty()).then_some(BackendChoice::Use(b))
+        }
+    }
+}
+
+/// The choice from `LIGHTCRAFT_GPU_BACKEND` (`lightcraft`) or else `WGPU_BACKEND` (`wgpu`): the
+/// first one that parses wins; an unknown value is skipped (with a warning).
+pub fn choose(lightcraft: Option<&str>, wgpu: Option<&str>) -> BackendChoice {
+    for (name, v) in [("LIGHTCRAFT_GPU_BACKEND", lightcraft), ("WGPU_BACKEND", wgpu)] {
+        let Some(v) = v else { continue };
+        match parse_backends(v) {
+            // WGPU_BACKEND is wgpu's variable: it selects backends, it never turns the GPU off
+            Some(BackendChoice::Off) if name == "WGPU_BACKEND" => log::warn!("gpu: WGPU_BACKEND={v} ignored (use LIGHTCRAFT_GPU_BACKEND=off)"),
+            Some(c) => return c,
+            None => log::warn!("gpu: {name}={v} names no known backend; ignored"),
+        }
+    }
+    BackendChoice::Auto
+}
+
+/// The backends compute devices use when nothing is asked for on `os` (`std::env::consts::OS`).
+pub fn default_compute_backends(os: &str) -> Backends {
+    match os {
+        // never touch the Vulkan driver unless asked: see the module docs (issue #136)
+        "windows" => Backends::DX12,
+        "macos" | "ios" => Backends::METAL,
+        _ => Backends::PRIMARY,
+    }
+}
+
+/// The backends the window uses when nothing is asked for on `os`.
+pub fn default_window_backends(os: &str) -> Backends {
+    match os {
+        "windows" => Backends::DX12,
+        "macos" | "ios" => Backends::METAL,
+        // eframe's default (GL only when the build has it)
+        _ => Backends::PRIMARY | Backends::GL,
+    }
+}
+
+/// Resolve `choice` against the backends this build contains (`compiled`): `None` = GPU off.
+/// Asked-for backends that aren't compiled in fall back to `default`.
+pub fn resolve(choice: BackendChoice, default: Backends, compiled: Backends) -> Option<Backends> {
+    match choice {
+        BackendChoice::Off => None,
+        BackendChoice::Auto => Some(default),
+        BackendChoice::Use(b) if b.intersects(compiled) => Some(b & compiled),
+        BackendChoice::Use(b) => {
+            log::warn!("gpu: backend {b:?} is not in this build ({compiled:?}); using {default:?}");
+            Some(default)
+        }
+    }
+}
+
+fn env_choice() -> BackendChoice {
+    static C: std::sync::OnceLock<BackendChoice> = std::sync::OnceLock::new();
+    *C.get_or_init(|| {
+        let lc = std::env::var("LIGHTCRAFT_GPU_BACKEND").ok();
+        let wg = std::env::var("WGPU_BACKEND").ok();
+        choose(lc.as_deref(), wg.as_deref())
+    })
+}
+
+/// The backends of the compute device (`None`: `LIGHTCRAFT_GPU_BACKEND=off`).
+pub fn compute_backends() -> Option<Backends> {
+    resolve(env_choice(), default_compute_backends(std::env::consts::OS), wgpu::Instance::enabled_backend_features())
+}
+
+/// The backends for the desktop window's renderer (eframe/egui-wgpu). The window always needs
+/// one: `off` keeps the platform default.
+pub fn window_backends() -> Backends {
+    let default = default_window_backends(std::env::consts::OS);
+    let choice = match env_choice() {
+        BackendChoice::Off => BackendChoice::Auto,
+        c => c,
+    };
+    resolve(choice, default, wgpu::Instance::enabled_backend_features()).unwrap_or(default)
+}
+
+/// `LIGHTCRAFT_GPU_BACKEND=off`.
+pub(crate) fn env_off() -> bool {
+    env_choice() == BackendChoice::Off
+}
+
+static MARKER: Mutex<Option<PathBuf>> = Mutex::new(None);
+
+/// Write this file before the compute device is created and remove it once creation returned
+/// (successfully or not). A file still there at the next launch means the process died inside
+/// the driver: see [`take_init_marker`]. `None` (the default) writes nothing.
+pub fn set_init_marker(path: Option<PathBuf>) {
+    *MARKER.lock().unwrap_or_else(|e| e.into_inner()) = path;
+}
+
+/// Run device creation `f` between writing and removing the init marker (if one is set).
+pub(crate) fn with_init_marker<T>(backends: Backends, f: impl FnOnce() -> T) -> T {
+    let marker = MARKER.lock().unwrap_or_else(|e| e.into_inner()).clone();
+    if let Some(m) = &marker {
+        if let Some(d) = m.parent() {
+            let _ = std::fs::create_dir_all(d);
+        }
+        let secs = std::time::SystemTime::now().duration_since(std::time::UNIX_EPOCH).map(|d| d.as_secs()).unwrap_or(0);
+        let _ = std::fs::write(m, format!("GPU device creation started (backends {backends:?}, unix time {secs})\n"));
+    }
+    let r = f();
+    if let Some(m) = &marker {
+        let _ = std::fs::remove_file(m);
+    }
+    r
+}
+
+/// If the init marker `path` is present — the last process died while creating the GPU device —
+/// remove it and return what it recorded.
+pub fn take_init_marker(path: &std::path::Path) -> Option<String> {
+    let text = std::fs::read_to_string(path).ok()?;
+    let _ = std::fs::remove_file(path);
+    Some(text.trim().to_string())
+}
+
+#[cfg(test)]
+#[allow(clippy::unwrap_used)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn parses_backend_names() {
+        assert_eq!(parse_backends("dx12"), Some(BackendChoice::Use(Backends::DX12)));
+        assert_eq!(parse_backends(" D3D12 "), Some(BackendChoice::Use(Backends::DX12)));
+        assert_eq!(parse_backends("vulkan"), Some(BackendChoice::Use(Backends::VULKAN)));
+        assert_eq!(parse_backends("vk,gl"), Some(BackendChoice::Use(Backends::VULKAN | Backends::GL)));
+        assert_eq!(parse_backends("metal"), Some(BackendChoice::Use(Backends::METAL)));
+        assert_eq!(parse_backends("auto"), Some(BackendChoice::Auto));
+        for off in ["off", "OFF", "none", "cpu", "0"] {
+            assert_eq!(parse_backends(off), Some(BackendChoice::Off), "{off}");
+        }
+        assert_eq!(parse_backends(""), None);
+        assert_eq!(parse_backends("directx9"), None);
+    }
+
+    #[test]
+    fn lightcraft_variable_wins_over_wgpu_backend() {
+        assert_eq!(choose(None, None), BackendChoice::Auto);
+        assert_eq!(choose(None, Some("dx12")), BackendChoice::Use(Backends::DX12));
+        assert_eq!(choose(Some("vulkan"), Some("dx12")), BackendChoice::Use(Backends::VULKAN));
+        assert_eq!(choose(Some("off"), Some("dx12")), BackendChoice::Off);
+        // unknown LightCraft value: WGPU_BACKEND still applies
+        assert_eq!(choose(Some("bogus"), Some("gl")), BackendChoice::Use(Backends::GL));
+        // WGPU_BACKEND never turns the GPU off
+        assert_eq!(choose(None, Some("off")), BackendChoice::Auto);
+    }
+
+    /// Issue #136: Windows must not load the Vulkan driver unless asked to.
+    #[test]
+    fn windows_defaults_to_dx12_only() {
+        assert_eq!(default_compute_backends("windows"), Backends::DX12);
+        assert_eq!(default_window_backends("windows"), Backends::DX12);
+        assert!(!default_window_backends("windows").contains(Backends::VULKAN));
+        assert_eq!(default_compute_backends("macos"), Backends::METAL);
+        assert!(default_compute_backends("linux").contains(Backends::VULKAN));
+        assert!(default_window_backends("linux").contains(Backends::VULKAN | Backends::GL));
+    }
+
+    #[test]
+    fn resolves_against_the_build() {
+        let compiled = Backends::DX12 | Backends::VULKAN;
+        let def = Backends::DX12;
+        assert_eq!(resolve(BackendChoice::Auto, def, compiled), Some(def));
+        assert_eq!(resolve(BackendChoice::Off, def, compiled), None);
+        assert_eq!(resolve(BackendChoice::Use(Backends::VULKAN), def, compiled), Some(Backends::VULKAN));
+        assert_eq!(resolve(BackendChoice::Use(Backends::VULKAN | Backends::GL), def, compiled), Some(Backends::VULKAN));
+        // GL isn't compiled in: the default, not an empty set (no adapter at all)
+        assert_eq!(resolve(BackendChoice::Use(Backends::GL), def, compiled), Some(def));
+    }
+
+    #[test]
+    fn init_marker_is_written_during_creation_and_removed_after() {
+        let dir = std::env::temp_dir().join(format!("lc-gpu-marker-{}", std::process::id()));
+        let m = dir.join("gpu-init.marker");
+        let _ = std::fs::remove_dir_all(&dir);
+        set_init_marker(Some(m.clone()));
+        let seen = with_init_marker(Backends::DX12, || m.exists());
+        set_init_marker(None);
+        assert!(seen, "the marker exists while the device is created");
+        assert!(!m.exists(), "and is removed afterwards");
+        // a marker left behind by a crashed process is reported once
+        std::fs::write(&m, "GPU device creation started (backends DX12)").unwrap();
+        assert!(take_init_marker(&m).unwrap().contains("DX12"));
+        assert_eq!(take_init_marker(&m), None);
+        let _ = std::fs::remove_dir_all(&dir);
+    }
+}

crates/gpu/src/ctx.rs

@@ -233,14 +233,16 @@ pub struct Gpu {
 /// WGSL constants shared by every module (generated from the CPU pipeline's values).
 fn constants() -> String {
     use lightcraft_pipeline::finish::{GRAIN_HASH, MASK_SUMS, MASK_TERMS, SRGB_LUT_N};
-    use lightcraft_pipeline::tone::{LUT_MAX_EV, LUT_MIN_EV, LUT_N};
+    use lightcraft_pipeline::tone::{CHROMA_N, LUT_MAX_EV, LUT_MIN_EV, LUT_N};
     let mut s = String::new();
     let [to_lms, from_lms, to_lab, from_lab] = lightcraft_color::perceptual::oklab_matrices();
     for (name, m) in [("OK_TO_LMS", to_lms), ("OK_FROM_LMS", from_lms), ("OK_TO_LAB", to_lab), ("OK_FROM_LAB", from_lab)] {
         let rows: Vec<String> = m.iter().map(|r| format!("vec3<f32>({:?}, {:?}, {:?})", r[0], r[1], r[2])).collect();
         s += &format!("const {name} = array<vec3<f32>, 3>({});\n", rows.join(", "));
     }
-    s += &format!("const TONE_MIN_EV: f32 = {LUT_MIN_EV:?};\nconst TONE_MAX_EV: f32 = {LUT_MAX_EV:?};\nconst TONE_N: u32 = {LUT_N}u;\n");
+    s += &format!(
+        "const TONE_MIN_EV: f32 = {LUT_MIN_EV:?};\nconst TONE_MAX_EV: f32 = {LUT_MAX_EV:?};\nconst TONE_N: u32 = {LUT_N}u;\nconst CHROMA_N: u32 = {CHROMA_N}u;\n"
+    );
     s += &format!("const TONE_MIN_GAIN: f32 = {:?};\n", 2f32.powf(LUT_MIN_EV));
     let b = lightcraft_pipeline::geometry::BLANK;
     s += &format!("const BLANK_R: f32 = {:?};\nconst BLANK_G: f32 = {:?};\nconst BLANK_B: f32 = {:?};\n", b[0], b[1], b[2]);
@@ -276,14 +278,15 @@ fn module_source(m: &Module, consts: &str) -> String {
 
 impl Gpu {
     /// Create a device on the best available adapter (no software fallback), or why there is none.
-    pub fn new() -> Result<Gpu, String> {
+    pub fn new(backends: wgpu::Backends) -> Result<Gpu, String> {
         let mut desc = wgpu::InstanceDescriptor::new_without_display_handle();
-        desc.backends = wgpu::Backends::PRIMARY;
+        // only these drivers are loaded (`crate::backend`: never Vulkan on Windows unless asked)
+        desc.backends = backends;
         let instance = wgpu::Instance::new(desc);
         let adapter = pollster::block_on(
             instance.request_adapter(&wgpu::RequestAdapterOptions { power_preference: wgpu::PowerPreference::HighPerformance, ..Default::default() }),
         )
-        .map_err(|e| format!("no GPU adapter ({e})"))?;
+        .map_err(|e| format!("no GPU adapter among {backends:?} ({e})"))?;
         let info = adapter.get_info();
         if info.device_type == wgpu::DeviceType::Cpu {
             log::info!("gpu: only a software adapter ({}), using the CPU pipeline", info.name);

crates/gpu/src/lib.rs

@@ -6,8 +6,11 @@
 //! same settings on both and bound the difference in 8-bit sRGB. Stages without a kernel run on the
 //! CPU inside the same render (per-stage hybrid); see `docs/gpu-pipeline.md`.
 //!
-//! Use [`render`]: it returns `None` when the GPU is unavailable, disabled (`LIGHTCRAFT_GPU=0` or
-//! [`set_enabled`]), the render does not fit the device, or the device reported an error, ran out
+//! Which backends wgpu may load (DX12 only on Windows; `LIGHTCRAFT_GPU_BACKEND`, `WGPU_BACKEND`) and
+//! the crash sentinel around device creation: [`backend`] (issue #136).
+//!
+//! Use [`render`]: it returns `None` when the GPU is unavailable, disabled (`LIGHTCRAFT_GPU=0`,
+//! `LIGHTCRAFT_GPU_BACKEND=off` or [`set_enabled`]), the render does not fit the device, or the device reported an error, ran out
 //! of memory or returned an incomplete image — callers then render on the CPU. [`unavailable_reason`]
 //! and [`last_fallback`] say why (`ui.inspect` → `perf.gpuReason` / `perf.gpuFallback`).
 //! The browser build has no GPU path yet (WebGPU device creation is asynchronous): everything here
@@ -22,6 +25,8 @@ use lightcraft_develop::DevelopSettings;
 use lightcraft_pipeline::{RenderRequest, Rendered, SourceInfo, StageCache};
 use lightcraft_raster::Rgb32f;
 
+#[cfg(not(target_arch = "wasm32"))]
+pub mod backend;
 #[cfg(not(target_arch = "wasm32"))]
 mod ctx;
 #[cfg(not(target_arch = "wasm32"))]
@@ -61,6 +66,10 @@ fn record_fallback(reason: String) {
 /// Never blocks.
 pub fn unavailable_reason() -> Option<String> {
     if env_disabled() {
+        #[cfg(not(target_arch = "wasm32"))]
+        if backend::env_off() {
+            return Some("disabled by LIGHTCRAFT_GPU_BACKEND=off".into());
+        }
         return Some("disabled by LIGHTCRAFT_GPU=0".into());
     }
     if !ENABLED.load(Ordering::Relaxed) {
@@ -136,9 +145,15 @@ pub fn enabled() -> bool {
     ENABLED.load(Ordering::Relaxed) && !BROKEN.load(Ordering::Relaxed) && !env_disabled()
 }
 
+/// `LIGHTCRAFT_GPU=0` (or `LIGHTCRAFT_GPU_BACKEND=off`): no GPU for the whole process.
 fn env_disabled() -> bool {
     static OFF: std::sync::OnceLock<bool> = std::sync::OnceLock::new();
-    *OFF.get_or_init(|| std::env::var("LIGHTCRAFT_GPU").is_ok_and(|v| matches!(v.trim(), "0" | "off" | "false" | "no")))
+    *OFF.get_or_init(|| {
+        let off = std::env::var("LIGHTCRAFT_GPU").is_ok_and(|v| matches!(v.trim(), "0" | "off" | "false" | "no"));
+        #[cfg(not(target_arch = "wasm32"))]
+        let off = off || backend::env_off();
+        off
+    })
 }
 
 #[cfg(not(target_arch = "wasm32"))]
@@ -146,10 +161,18 @@ static GPU: std::sync::OnceLock<Result<ctx::Gpu, String>> = std::sync::OnceLock:
 
 #[cfg(not(target_arch = "wasm32"))]
 pub(crate) fn device() -> Option<&'static ctx::Gpu> {
-    if env_disabled() {
-        return None;
+    // turned off (preference, environment): don't even load the driver (issue #136)
+    if env_disabled() || !ENABLED.load(Ordering::Relaxed) {
+        return existing_device();
     }
-    GPU.get_or_init(|| std::panic::catch_unwind(ctx::Gpu::new).unwrap_or_else(|_| Err("device creation panicked".into()))).as_ref().ok()
+    GPU.get_or_init(|| {
+        let Some(backends) = backend::compute_backends() else { return Err("disabled by LIGHTCRAFT_GPU_BACKEND=off".into()) };
+        backend::with_init_marker(backends, || {
+            std::panic::catch_unwind(|| ctx::Gpu::new(backends)).unwrap_or_else(|_| Err("device creation panicked".into()))
+        })
+    })
+    .as_ref()
+    .ok()
 }
 
 /// The device if it has been created (never creates it).
@@ -158,11 +181,12 @@ pub(crate) fn existing_device() -> Option<&'static ctx::Gpu> {
     GPU.get().and_then(|g| g.as_ref().ok())
 }
 
-/// Create the device and compile the kernels on a background thread now (app start), so the
-/// first render doesn't wait ~0.3–0.4 s for it and the UI thread never does.
+/// Create the device and compile the kernels on a background thread now (once the window is up),
+/// so the first render doesn't wait ~0.3–0.4 s for it and the UI thread never does. Does nothing
+/// while GPU rendering is turned off.
 pub fn warm_up() {
     #[cfg(not(target_arch = "wasm32"))]
-    if !env_disabled() && GPU.get().is_none() {
+    if !env_disabled() && ENABLED.load(Ordering::Relaxed) && GPU.get().is_none() {
         let _ = std::thread::Builder::new().name("lc-gpu-init".into()).spawn(|| {
             let _ = device();
         });

crates/gpu/src/params.rs

@@ -136,10 +136,11 @@ pub struct Present {
     pub chroma: bool,
 }
 
-/// The `finish` kernel's parameter block and auxiliary table (tone LUT | sRGB LUT | curve LUTs |
+/// The `finish` kernel's parameter block and auxiliary table (tone LUT | chroma curve | sRGB LUT | curve LUTs |
 /// mask terms) for `fp` with `masks` (their local adjustments' terms).
 pub fn finish_block(fp: &FinishParams, masks: &[[f32; MASK_TERMS]], present: &Present) -> (Vec<u32>, Vec<f32>) {
     let mut aux: Vec<f32> = fp.tone.lut().to_vec();
+    aux.extend_from_slice(fp.tone.chroma_lut());
     let srgb_off = aux.len();
     aux.extend_from_slice(&srgb_lut()[..]);
     let curve_off = aux.len();

crates/gpu/src/wgsl/finish.wgsl

@@ -1,7 +1,7 @@
 // The per-pixel stage: a straight port of `lightcraft_pipeline::finish` (keep in step with it).
 // Bindings: img (rgb, pre-exposure), log_l, base, clar, tex, dark, masks (NMASK planes, then the
 // blurred chromaticity when HAS_CHROMA), aux
-// (tone LUT | sRGB LUT | curve LUTs | mask terms), out (packed RGBA8).
+// (tone LUT | chroma curve | sRGB LUT | curve LUTs | mask terms), out (packed RGBA8).
 
 fn tone_apply(y: f32) -> f32 {
     if (y <= 0.0) {
@@ -18,6 +18,19 @@ fn tone_apply(y: f32) -> f32 {
     return v;
 }
 
+// The camera chroma curve follows the tone LUT in `aux` (`ToneMap::chroma_scale`).
+fn chroma_scale(o: f32) -> f32 {
+    let f = clamp(o, 0.0, 1.0) * f32(CHROMA_N - 1u);
+    let i = min(u32(f), CHROMA_N - 2u);
+    let t = f - f32(i);
+    let a = aux[TONE_N + i];
+    let b = aux[TONE_N + i + 1u];
+    if (a == b) {
+        return a;
+    }
+    return a + (b - a) * t;
+}
+
 fn encode_srgb(v: f32) -> f32 {
     let o = pu(F_SRGB_OFF);
     let f = clamp(v, 0.0, 1.0) * f32(SRGB_N);
@@ -400,6 +413,10 @@ fn main(@builtin(global_invocation_id) gid: vec3<u32>) {
     if (yl > 1e-9) {
         d = c * o / yl;
     }
+    let k = chroma_scale(o);
+    if (k != 1.0) {
+        d = vec3<f32>(o) + (d - vec3<f32>(o)) * k;
+    }
     let mx = max(d.x, max(d.y, d.z));
     if (mx > 1.0) {
         let t = clamp((mx - 1.0) / max(mx - o, 1e-6), 0.0, 1.0);

crates/gpu/tests/equivalence.rs

@@ -22,6 +22,32 @@ fn gpu() -> bool {
     ok
 }
 
+#[test]
+fn camera_tone_and_relative_wb() {
+    if !gpu() {
+        return;
+    }
+    let src = scene(2, 320, 240);
+    let curve = lightcraft_pipeline::tone::CameraTone::new(std::array::from_fn(|i| {
+        let x = 0.004 * 1.18f32.powi(i as i32);
+        [x, 1.0 - (-2.0 * x).exp()]
+    }))
+    .unwrap();
+    let info = SourceInfo { raw: true, relative_wb: true, camera_tone: Some(curve), ..Default::default() };
+    let mut s = DevelopSettings::default();
+    check("camera tone neutral", &src, &info, &s, &RenderRequest::fit(320, 240));
+    s.light.exposure = 1.0;
+    s.light.contrast = 40.0;
+    s.wb.mode = WbMode::Custom;
+    s.wb.temp = 8000.0;
+    check("camera tone edited", &src, &info, &s, &RenderRequest::fit(320, 240));
+    // a camera chroma curve: richer shadows, highlights bleached toward white
+    let curve = curve.with_chroma([1.4, 1.3, 1.1, 1.0, 0.7, 0.4, 0.25, 0.2]).unwrap();
+    let info = SourceInfo { camera_tone: Some(curve), ..info };
+    check("camera chroma curve", &src, &info, &DevelopSettings::default(), &RenderRequest::fit(320, 240));
+    check("camera chroma curve edited", &src, &info, &s, &RenderRequest::fit(320, 240));
+}
+
 fn scene(i: usize, w: usize, h: usize) -> Arc<Rgb32f> {
     Arc::new(lightcraft_scenes::demo_library()[i].render(w, h))
 }

crates/merge/src/output.rs

@@ -45,6 +45,7 @@ pub fn color_data(color: &FrameColor) -> ColorData {
                 as_shot_neutral: Some([1.0, 1.0, 1.0]),
                 as_shot_white_xy: None,
                 baseline_exposure: 0.0,
+                profile: Default::default(),
             }
         }
     }

crates/meta/src/container.rs

@@ -7,6 +7,8 @@
 //! - WebP (RIFF container spec): `EXIF`, `XMP `, `ICCP` chunks.
 //! - TIFF-based files (TIFF, DNG and most raws): the whole file is the Exif block; XMP (700), ICC (34675) and
 //!   IPTC (33723) from IFD0.
+//! - Canon CR3 (ISO base media file, see [`crate::cr3`]): `CMT1`/`CMT2`/`CMT4` merged into one Exif block; the
+//!   XMP `uuid` box.
 
 use lightcraft_tiff::{Tiff, tags};
 
@@ -34,6 +36,9 @@ pub fn embedded(bytes: &[u8]) -> Embedded {
             _ => Embedded::default(),
         };
     }
+    if let Some(c) = crate::cr3::parse_cr3(bytes) {
+        return Embedded { exif: crate::cr3::merged_exif(&c), xmp: c.xmp.map(|b| String::from_utf8_lossy(b).into_owned()), ..Default::default() };
+    }
     if bytes.starts_with(&[0xff, 0xd8]) {
         jpeg_segments(bytes)
     } else if bytes.starts_with(b"\x89PNG\r\n\x1a\n") {

crates/meta/src/cr3.rs

@@ -0,0 +1,344 @@
+//! Canon CR3: the ISO base media file container (ISO/IEC 14496-12 box structure; CR3 layout from Laurent
+//! Clévy's public CR3 format notes, confirmed black-box on EOS R6 Mark III files).
+//!
+//! - `ftyp` with major brand `crx `.
+//! - `moov` holds a Canon `uuid` box (85c0b687-820f-11e0-8111-f4ce462b6a48) whose children are `CMT1` (a TIFF
+//!   stream: IFD0), `CMT2` (TIFF: the Exif IFD), `CMT3` (TIFF: the Canon maker note), `CMT4` (TIFF: GPS) and the
+//!   `THMB` thumbnail, then one `trak` per stream: a full-size JPEG, a reduced raw, the full raw (`CRAW` sample
+//!   entries; raws carry a `CMP1` coding header) and timed metadata (`CTMD`).
+//! - A top-level `uuid` box with the XMP uuid (be7acfcb-97a9-42e8-9c71-999491e3afac, XMP spec part 3) holds the
+//!   XMP packet.
+//!
+//! Every size and offset is checked against the buffer; nesting and box counts are bounded.
+
+/// A track's sample-entry kind.
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub enum Cr3TrackKind {
+    /// `CRAW` with a `JPEG` child: the full-size JPEG.
+    Jpeg,
+    /// `CRAW` raw image: dimensions and the `CMP1` coding header (byte range in the file).
+    Raw { width: u16, height: u16, cmp1: Option<(usize, usize)> },
+    /// Anything else (`CTMD` timed metadata, unknown entries).
+    Other([u8; 4]),
+}
+
+/// One track's single sample: where it is in the file.
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub struct Cr3Track {
+    pub kind: Cr3TrackKind,
+    /// Byte offset and length of the sample (the first one) in the file, when the tables give them.
+    pub data: Option<(usize, usize)>,
+}
+
+/// The parts of a CR3 file LightCraft reads.
+#[derive(Clone, Debug, Default, PartialEq, Eq)]
+pub struct Cr3<'a> {
+    /// `CMT1`…`CMT4` (index 0…3).
+    pub cmt: [Option<&'a [u8]>; 4],
+    pub thumbnail: Option<&'a [u8]>,
+    pub xmp: Option<&'a [u8]>,
+    pub tracks: Vec<Cr3Track>,
+}
+
+const CANON_UUID: [u8; 16] = [0x85, 0xc0, 0xb6, 0x87, 0x82, 0x0f, 0x11, 0xe0, 0x81, 0x11, 0xf4, 0xce, 0x46, 0x2b, 0x6a, 0x48];
+const XMP_UUID: [u8; 16] = [0xbe, 0x7a, 0xcf, 0xcb, 0x97, 0xa9, 0x42, 0xe8, 0x9c, 0x71, 0x99, 0x94, 0x91, 0xe3, 0xaf, 0xac];
+const MAX_DEPTH: usize = 12;
+const MAX_BOXES: usize = 4096;
+/// A `VisualSampleEntry` (78 bytes after the box header) plus 4 bytes Canon adds before the child boxes.
+const CRAW_CHILDREN_AT: usize = 82;
+
+/// Does this look like a CR3 file (`ftyp` box with major brand `crx `)?
+pub fn is_cr3(bytes: &[u8]) -> bool {
+    bytes.get(4..12) == Some(b"ftypcrx ".as_slice())
+}
+
+/// Parse a CR3 file's boxes; `None` when it is not a CR3 file.
+pub fn parse_cr3(bytes: &[u8]) -> Option<Cr3<'_>> {
+    if !is_cr3(bytes) {
+        return None;
+    }
+    let mut out = Cr3::default();
+    let mut budget = MAX_BOXES;
+    for b in boxes(bytes, 0, bytes.len(), &mut budget) {
+        match &b.kind {
+            b"moov" => moov(bytes, &b, &mut out, &mut budget),
+            b"uuid" if b.uuid == Some(XMP_UUID) => out.xmp = bytes.get(b.body..b.end),
+            _ => {}
+        }
+    }
+    Some(out)
+}
+
+struct BoxRef {
+    kind: [u8; 4],
+    /// Start of the payload (after the header and, for `uuid`, the 16-byte uuid).
+    body: usize,
+    end: usize,
+    uuid: Option<[u8; 16]>,
+}
+
+/// The boxes directly inside `[from, to)`; stops at the first malformed header.
+fn boxes(bytes: &[u8], from: usize, to: usize, budget: &mut usize) -> Vec<BoxRef> {
+    let mut out = Vec::new();
+    let mut at = from;
+    let to = to.min(bytes.len());
+    while at.saturating_add(8) <= to && *budget > 0 {
+        *budget -= 1;
+        let (Some(size), Some(kind)) = (be32(bytes, at), bytes.get(at + 4..at + 8)) else { break };
+        let mut kind4 = [0u8; 4];
+        kind4.copy_from_slice(kind);
+        let (len, mut hdr) = match size {
+            0 => (to - at, 8),
+            1 => match be64(bytes, at + 8).and_then(|v| usize::try_from(v).ok()) {
+                Some(l) => (l, 16),
+                None => break,
+            },
+            n => (n as usize, 8),
+        };
+        let Some(end) = at.checked_add(len).filter(|&e| e <= to && len >= hdr) else { break };
+        let mut uuid = None;
+        if &kind4 == b"uuid" {
+            let Some(u) = bytes.get(at + hdr..at + hdr + 16).filter(|_| at + hdr + 16 <= end) else { break };
+            let mut a = [0u8; 16];
+            a.copy_from_slice(u);
+            uuid = Some(a);
+            hdr += 16;
+        }
+        out.push(BoxRef { kind: kind4, body: at + hdr, end, uuid });
+        at = end;
+    }
+    out
+}
+
+fn moov<'a>(bytes: &'a [u8], m: &BoxRef, out: &mut Cr3<'a>, budget: &mut usize) {
+    for b in boxes(bytes, m.body, m.end, budget) {
+        match &b.kind {
+            b"uuid" if b.uuid == Some(CANON_UUID) => {
+                for c in boxes(bytes, b.body, b.end, budget) {
+                    let slot = match &c.kind {
+                        b"CMT1" => 0,
+                        b"CMT2" => 1,
+                        b"CMT3" => 2,
+                        b"CMT4" => 3,
+                        b"THMB" => {
+                            out.thumbnail = bytes.get(c.body..c.end);
+                            continue;
+                        }
+                        _ => continue,
+                    };
+                    out.cmt[slot] = bytes.get(c.body..c.end);
+                }
+            }
+            b"trak" => {
+                if let Some(t) = trak(bytes, &b, budget) {
+                    out.tracks.push(t);
+                }
+            }
+            _ => {}
+        }
+    }
+}
+
+/// Descend `trak` → `mdia` → `minf` → `stbl` and read its sample entry and first sample's location.
+fn trak(bytes: &[u8], t: &BoxRef, budget: &mut usize) -> Option<Cr3Track> {
+    let mut stbl = None;
+    let mut stack = vec![(t.body, t.end, 0usize)];
+    while let Some((from, to, depth)) = stack.pop() {
+        if depth > MAX_DEPTH {
+            continue;
+        }
+        for b in boxes(bytes, from, to, budget) {
+            match &b.kind {
+                b"mdia" | b"minf" => stack.push((b.body, b.end, depth + 1)),
+                b"stbl" => stbl = Some(b),
+                _ => {}
+            }
+        }
+    }
+    let stbl = stbl?;
+    let (mut kind, mut size, mut offset) = (None, None, None);
+    for b in boxes(bytes, stbl.body, stbl.end, budget) {
+        match &b.kind {
+            // full box: version/flags, entry count, entries
+            b"stsd" => kind = boxes(bytes, b.body + 8, b.end, budget).first().map(|e| sample_entry(bytes, e, budget)),
+            // version/flags, sample_size (0 = per-sample table), count, sizes
+            b"stsz" => {
+                size = match be32(bytes, b.body + 4)? {
+                    0 if be32(bytes, b.body + 8)? > 0 => be32(bytes, b.body + 12),
+                    0 => None,
+                    n => Some(n),
+                }
+            }
+            b"co64" if be32(bytes, b.body + 4)? > 0 => offset = be64(bytes, b.body + 8).and_then(|v| usize::try_from(v).ok()),
+            b"stco" if be32(bytes, b.body + 4)? > 0 => offset = be32(bytes, b.body + 8).map(|v| v as usize),
+            _ => {}
+        }
+    }
+    let data = match (offset, size) {
+        (Some(o), Some(s)) if o.checked_add(s as usize).is_some_and(|e| e <= bytes.len()) => Some((o, s as usize)),
+        _ => None,
+    };
+    Some(Cr3Track { kind: kind?, data })
+}
+
+fn sample_entry(bytes: &[u8], e: &BoxRef, budget: &mut usize) -> Cr3TrackKind {
+    if &e.kind != b"CRAW" {
+        return Cr3TrackKind::Other(e.kind);
+    }
+    let (Some(width), Some(height)) = (be16(bytes, e.body + 24), be16(bytes, e.body + 26)) else {
+        return Cr3TrackKind::Other(e.kind);
+    };
+    let mut cmp1 = None;
+    for c in boxes(bytes, e.body.saturating_add(CRAW_CHILDREN_AT), e.end, budget) {
+        match &c.kind {
+            b"JPEG" => return Cr3TrackKind::Jpeg,
+            b"CMP1" => cmp1 = Some((c.body, c.end - c.body)),
+            _ => {}
+        }
+    }
+    Cr3TrackKind::Raw { width, height, cmp1 }
+}
+
+fn be16(b: &[u8], at: usize) -> Option<u16> {
+    b.get(at..at.checked_add(2)?).map(|s| u16::from_be_bytes([s[0], s[1]]))
+}
+fn be32(b: &[u8], at: usize) -> Option<u32> {
+    b.get(at..at.checked_add(4)?).map(|s| u32::from_be_bytes([s[0], s[1], s[2], s[3]]))
+}
+fn be64(b: &[u8], at: usize) -> Option<u64> {
+    let s = b.get(at..at.checked_add(8)?)?;
+    let mut a = [0u8; 8];
+    a.copy_from_slice(s);
+    Some(u64::from_be_bytes(a))
+}
+
+/// Merge `CMT1` (IFD0), `CMT2` (Exif) and `CMT4` (GPS) into one TIFF stream, so the Exif readers see a CR3
+/// like any TIFF-based raw. The maker note (`CMT3`) is left out: its offsets are relative to its own block.
+pub fn merged_exif(c: &Cr3<'_>) -> Option<Vec<u8>> {
+    use lightcraft_tiff::{IfdBuilder, Tiff, TiffWriter, tags as t};
+    let ifd0 = Tiff::parse(c.cmt[0]?).ok()?;
+    let order = ifd0.order;
+    let first = |i: usize| c.cmt[i].and_then(|b| Tiff::parse(b).ok()).and_then(|t| t.ifds.into_iter().next());
+    // pointers and offsets that would dangle once the IFDs move
+    const SKIP: [u16; 9] = [t::EXIF_IFD, t::GPS_IFD, t::INTEROP_IFD, t::SUB_IFDS, t::MAKER_NOTE, 273, 279, 513, 514];
+    let build = |ifd: &lightcraft_tiff::Ifd| {
+        let mut b = IfdBuilder::new();
+        for e in ifd.entries.iter().filter(|e| !SKIP.contains(&e.tag)) {
+            b.set(e.tag, e.value.clone());
+        }
+        b
+    };
+    let mut root = build(ifd0.ifds.first()?);
+    if let Some(exif) = first(1) {
+        root.set_child(t::EXIF_IFD, build(&exif));
+    }
+    if let Some(gps) = first(3) {
+        root.set_child(t::GPS_IFD, build(&gps));
+    }
+    TiffWriter::new(order, false).write(&[root]).ok()
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn bx(kind: &[u8; 4], body: &[u8]) -> Vec<u8> {
+        let mut v = ((body.len() + 8) as u32).to_be_bytes().to_vec();
+        v.extend_from_slice(kind);
+        v.extend_from_slice(body);
+        v
+    }
+    fn uuid(u: &[u8; 16], body: &[u8]) -> Vec<u8> {
+        let mut b = u.to_vec();
+        b.extend_from_slice(body);
+        bx(b"uuid", &b)
+    }
+    fn full(kind: &[u8; 4], body: &[u8]) -> Vec<u8> {
+        let mut b = vec![0u8; 4];
+        b.extend_from_slice(body);
+        bx(kind, &b)
+    }
+    fn craw(w: u16, h: u16, children: &[u8]) -> Vec<u8> {
+        let mut b = vec![0u8; CRAW_CHILDREN_AT];
+        b[24..26].copy_from_slice(&w.to_be_bytes());
+        b[26..28].copy_from_slice(&h.to_be_bytes());
+        b.extend_from_slice(children);
+        bx(b"CRAW", &b)
+    }
+    fn trak(entry: Vec<u8>, offset: u64, size: u32) -> Vec<u8> {
+        let mut stsd = 1u32.to_be_bytes().to_vec();
+        stsd.extend(entry);
+        let mut stsz = 0u32.to_be_bytes().to_vec();
+        stsz.extend(1u32.to_be_bytes());
+        stsz.extend(size.to_be_bytes());
+        let mut co64 = 1u32.to_be_bytes().to_vec();
+        co64.extend(offset.to_be_bytes());
+        let stbl = [full(b"stsd", &stsd), full(b"stsz", &stsz), full(b"co64", &co64)].concat();
+        bx(b"trak", &bx(b"mdia", &bx(b"minf", &bx(b"stbl", &stbl))))
+    }
+    fn tiff_with(tag: u16, v: lightcraft_tiff::Value) -> Vec<u8> {
+        let b = lightcraft_tiff::IfdBuilder::new().with(tag, v);
+        lightcraft_tiff::TiffWriter::new(lightcraft_tiff::ByteOrder::Little, false).write(&[b]).unwrap()
+    }
+
+    /// A small synthetic CR3: Canon uuid with CMT1/CMT2/CMT4, a JPEG track, a raw track, XMP.
+    pub(crate) fn sample() -> Vec<u8> {
+        use lightcraft_tiff::{Value, tags as t};
+        let cmt1 = tiff_with(t::MODEL, Value::Ascii("Canon EOS Test".into()));
+        let cmt2 = tiff_with(t::ISO_SPEED, Value::Short(vec![400]));
+        let cmt4 = tiff_with(1, Value::Ascii("N".into()));
+        let canon = uuid(&CANON_UUID, &[bx(b"CMT1", &cmt1), bx(b"CMT2", &cmt2), bx(b"CMT4", &cmt4), bx(b"THMB", b"thumb")].concat());
+        let mut file = bx(b"ftyp", b"crx \0\0\0\x01crx isom");
+        let payload_at = 4096u64;
+        let jpeg_t = trak(craw(64, 48, &bx(b"JPEG", &[0; 4])), payload_at, 16);
+        let raw_t = trak(craw(60, 40, &bx(b"CMP1", &[0xff, 0x10, 0, 0x30])), payload_at + 16, 32);
+        file.extend(bx(b"moov", &[canon, jpeg_t, raw_t].concat()));
+        file.extend(uuid(&XMP_UUID, b"<x:xmpmeta/>"));
+        file.resize(payload_at as usize + 64, 0);
+        file
+    }
+
+    #[test]
+    fn parses_canon_boxes_tracks_and_xmp() {
+        let f = sample();
+        assert!(is_cr3(&f));
+        let c = parse_cr3(&f).unwrap();
+        assert!(c.cmt[0].is_some() && c.cmt[1].is_some() && c.cmt[2].is_none() && c.cmt[3].is_some());
+        assert_eq!(c.thumbnail, Some(b"thumb".as_slice()));
+        assert_eq!(c.xmp, Some(b"<x:xmpmeta/>".as_slice()));
+        assert_eq!(c.tracks.len(), 2);
+        assert_eq!(c.tracks[0], Cr3Track { kind: Cr3TrackKind::Jpeg, data: Some((4096, 16)) });
+        let Cr3TrackKind::Raw { width, height, cmp1: Some((at, len)) } = c.tracks[1].kind else { panic!("{:?}", c.tracks[1]) };
+        assert_eq!((width, height, len), (60, 40, 4));
+        assert_eq!(&f[at..at + 2], &[0xff, 0x10]);
+        assert_eq!(c.tracks[1].data, Some((4112, 32)));
+    }
+
+    #[test]
+    fn merged_exif_reads_like_a_tiff_raw() {
+        let f = sample();
+        let m = crate::read_exif(&merged_exif(&parse_cr3(&f).unwrap()).unwrap());
+        assert_eq!(m.model.as_deref(), Some("Canon EOS Test"));
+        assert_eq!(m.iso, Some(400));
+    }
+
+    #[test]
+    fn hostile_input_never_panics() {
+        let f = sample();
+        // every truncation and single-byte corruption parses to something or nothing
+        for n in 0..f.len().min(800) {
+            let _ = parse_cr3(&f[..n]).map(|c| merged_exif(&c));
+        }
+        for i in 0..f.len().min(800) {
+            for v in [0u8, 1, 0x7f, 0xff] {
+                let mut g = f.clone();
+                g[i] = v;
+                let _ = parse_cr3(&g).map(|c| merged_exif(&c));
+            }
+        }
+        // a sample offset past the end is not reported
+        let mut g = f.clone();
+        g.truncate(4100);
+        assert!(parse_cr3(&g).unwrap().tracks.iter().all(|t| t.data.is_none()));
+    }
+}

crates/meta/src/lib.rs

@@ -7,10 +7,12 @@
 //! - [`parse_xmp`] / [`write_xmp`] — XMP packets (interchange fields + the opaque `lc:settings` JSON).
 //! - [`parse_iptc`] — IPTC-IIM record 2 datasets.
 //! - [`parse_gpx`] — GPS track logs (GPX) for geotagging by capture time.
-//! - [`extract`] — all of the above for a whole file (JPEG, PNG, WebP, TIFF/DNG/raw).
+//! - [`extract`] — all of the above for a whole file (JPEG, PNG, WebP, TIFF/DNG/raw, Canon CR3).
+//! - [`cr3`] — the Canon CR3 container (metadata blocks, XMP, the JPEG and raw tracks).
 #![forbid(unsafe_code)]
 
 mod container;
+pub mod cr3;
 mod datetime;
 mod exif;
 mod gpx;
@@ -24,7 +26,7 @@ pub use datetime::DateTime;
 pub use exif::{from_tiff, read_exif, strip_exif_header, try_read_exif, write_exif};
 pub use gpx::{GpxError, Match, TrackPoint, Tracklog, parse_gpx};
 pub use iptc::parse_iptc;
-pub use lightcraft_geom::Orientation;
+pub use lightcraft_geom::{Orientation, Rect};
 pub use tags::{TagRow, file_tag_rows, tag_rows};
 pub use xmp::{CRS_NS, LC_NS, XmpData, XmpError, XmpValue, parse_xmp, write_xmp, write_xmp_lc};
 pub use xmp_merge::{MergeRules, merge_xmp};
@@ -48,6 +50,31 @@ pub struct Flash {
     pub raw: u16,
 }
 
+/// A named region of interest on a photo (MWG Region Guidelines, `mwg-rs:Regions`): most often a face,
+/// drawn by Lightroom, digiKam, Picasa or similar tools. Read-only for now — LightCraft does not write
+/// regions yet (see `docs/xmp-interop.md`).
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
+pub struct Region {
+    /// Normalized to the image's full, oriented frame (`Metadata::width`/`height`), y-down, 0..1 on
+    /// both axes — MWG's own convention, and what `AppliedToDimensions` areas are converted to.
+    pub rect: Rect,
+    pub kind: RegionKind,
+    /// `mwg-rs:Name` (e.g. the person's name).
+    pub name: Option<String>,
+    pub description: Option<String>,
+}
+
+/// `mwg-rs:Type`. Unrecognised values are kept verbatim rather than dropped.
+#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize)]
+pub enum RegionKind {
+    Face,
+    Pet,
+    Focus,
+    BarCode,
+    /// `mwg-rs:Type` was missing, empty, or a value we don't recognise.
+    Other(String),
+}
+
 /// Everything LightCraft shows or searches about a photo. All fields are optional; unknown = `None`/empty.
 #[derive(Clone, Debug, Default, PartialEq, Serialize, Deserialize)]
 pub struct Metadata {
@@ -113,6 +140,8 @@ pub struct Metadata {
     pub rating: Option<i8>,
     /// Colour label name (e.g. "Red").
     pub label: Option<String>,
+    /// Face/pet/focus/barcode regions (`mwg-rs:Regions`), read from XMP only.
+    pub regions: Vec<Region>,
 }
 
 macro_rules! fill {
@@ -173,6 +202,9 @@ impl Metadata {
         if self.hierarchical_keywords.is_empty() {
             self.hierarchical_keywords = other.hierarchical_keywords.clone();
         }
+        if self.regions.is_empty() {
+            self.regions = other.regions.clone();
+        }
     }
 
     /// Replace the user-editable fields (rating, label, title, caption, artist, copyright, keywords, GPS) with
@@ -185,6 +217,9 @@ impl Metadata {
         if !other.hierarchical_keywords.is_empty() {
             self.hierarchical_keywords = other.hierarchical_keywords.clone();
         }
+        if !other.regions.is_empty() {
+            self.regions = other.regions.clone();
+        }
     }
 
     /// Exposure time formatted like cameras show it: `1/250`, `0.5`, `2″`.

crates/meta/src/xmp.rs

@@ -8,7 +8,8 @@
 //! Writing emits the interchange subset in standard namespaces (dc, xmp, photoshop, exif, exifEX, tiff, lr) and
 //! LightCraft's full develop settings as an opaque JSON string in `lc:settings`.
 
-use crate::{DateTime, Flash, Gps, Metadata, Orientation, parse_number};
+use crate::{DateTime, Flash, Gps, Metadata, Orientation, Region, RegionKind, parse_number};
+use lightcraft_geom::{Point, Rect};
 use quick_xml::escape::{escape, partial_escape};
 use quick_xml::events::Event;
 use std::collections::BTreeMap;
@@ -32,6 +33,11 @@ const NAMESPACES: &[(&str, &str)] = &[
     ("lc", LC_NS),
     // Read-only: develop settings written by other raw developers (interchange; see docs/xmp-interop.md).
     ("crs", CRS_NS),
+    // Read-only: face/pet/focus regions written by Lightroom, digiKam, Picasa and others (MWG Region
+    // Guidelines v2.0). Canonicalising these three lets a packet use any prefix for them.
+    ("mwg-rs", "http://www.metadataworkinggroup.com/schemas/regions/"),
+    ("stArea", "http://ns.adobe.com/xmp/sType/Area#"),
+    ("stDim", "http://ns.adobe.com/xap/1.0/sType/Dimensions#"),
 ];
 
 /// The camera-raw-settings namespace URI (prefix `crs`), read for interchange only.
@@ -374,6 +380,72 @@ fn parse_gps_coord(s: &str) -> Option<f64> {
     v.is_finite().then_some(v)
 }
 
+/// `mwg-rs:Regions` → every region in its `RegionList`, converted to the full-image normalized frame.
+/// Malformed or out-of-range entries are skipped rather than rejecting the whole list: one bad region
+/// (from Lightroom, digiKam, Picasa, or a hand-edited file) shouldn't hide the rest.
+fn parse_regions(regions: &XmpValue) -> Vec<Region> {
+    // `AppliedToDimensions` documents the pixel size regions were authored against. It's only consulted
+    // for the rare region whose own Area is in pixel units instead of MWG's normalized default below.
+    let px_dims = regions.field("mwg-rs:AppliedToDimensions").and_then(|d| {
+        let w = d.field("stDim:w").and_then(XmpValue::text).and_then(parse_number)?;
+        let h = d.field("stDim:h").and_then(XmpValue::text).and_then(parse_number)?;
+        (w > 0.0 && h > 0.0).then_some((w, h))
+    });
+    let Some(list) = regions.field("mwg-rs:RegionList") else { return Vec::new() };
+    list.items().iter().filter_map(|item| parse_one_region(item, px_dims)).collect()
+}
+
+fn parse_one_region(item: &XmpValue, px_dims: Option<(f64, f64)>) -> Option<Region> {
+    let area = item.field("mwg-rs:Area")?;
+    let num_attr = |k: &str| area.field(k).and_then(XmpValue::text).and_then(parse_number);
+    // stArea:x/y are the region's CENTER, not its top-left corner (MWG Region Guidelines §Area).
+    let (cx, cy, w, h) = (num_attr("stArea:x")?, num_attr("stArea:y")?, num_attr("stArea:w")?, num_attr("stArea:h")?);
+    let finite_and_sane = [cx, cy, w, h].iter().all(|v| v.is_finite() && v.abs() <= 1.0e6);
+    if !finite_and_sane || w <= 0.0 || h <= 0.0 {
+        return None;
+    }
+    // `stArea:unit` is "normalized" (a fraction of AppliedToDimensions) in every writer we know of, and
+    // that needs no cross-referencing at all. Only a region that explicitly says "pixel" gets divided
+    // down, and only if AppliedToDimensions is there to divide by; otherwise it's dropped rather than
+    // stored as a nonsense fraction.
+    let is_pixels = area.field("stArea:unit").and_then(XmpValue::text).is_some_and(|u| u.eq_ignore_ascii_case("pixel"));
+    let (cx, cy, w, h) = match (is_pixels, px_dims) {
+        (false, _) => (cx, cy, w, h),
+        (true, Some((dw, dh))) => (cx / dw, cy / dh, w / dw, h / dh),
+        (true, None) => return None,
+    };
+    // Lightroom Classic stores the box of a photo with Exif orientation 3 / 6 / 8 in the sensor's own
+    // frame and writes the orientation as the region's `mwg-rs:Rotation` (π for 3, −π/2 for 6, +π/2 for
+    // 8; 0 for 1) while `AppliedToDimensions` names the upright size. Turn it into the upright frame.
+    // MWG has no way to say "mirrored", so orientations 2/4/5/7 can't be told apart from their unmirrored
+    // twins here; boxes on mirrored photos are taken as written (see LR-LIB-PEOPLE in docs/parity.md).
+    let rotation = item.field("mwg-rs:Rotation").and_then(XmpValue::text).and_then(parse_number).filter(|r| r.is_finite());
+    let (quarter, half) = (std::f64::consts::FRAC_PI_2, std::f64::consts::PI);
+    let (cx, cy, w, h) = match rotation {
+        Some(r) if (r + quarter).abs() < 0.05 => (1.0 - cy, cx, h, w),
+        Some(r) if (r - quarter).abs() < 0.05 => (cy, 1.0 - cx, h, w),
+        Some(r) if (r.abs() - half).abs() < 0.05 => (1.0 - cx, 1.0 - cy, w, h),
+        _ => (cx, cy, w, h),
+    };
+    // Keep only the part of the box inside the photo: a region hanging off an edge (common for faces
+    // cut by the frame) is clipped, and one entirely outside it (hostile or stale) is dropped, so every
+    // stored rect is within 0..1 and non-empty.
+    let rect = Rect::from_center(Point::new(cx, cy), w, h).intersect(&Rect::UNIT);
+    if rect.is_empty() {
+        return None;
+    }
+    let name = item.field("mwg-rs:Name").and_then(XmpValue::text).map(str::to_string).filter(|s| !s.is_empty());
+    let description = item.field("mwg-rs:Description").and_then(XmpValue::text).map(str::to_string).filter(|s| !s.is_empty());
+    let kind = match item.field("mwg-rs:Type").and_then(XmpValue::text).unwrap_or("") {
+        t if t.eq_ignore_ascii_case("face") => RegionKind::Face,
+        t if t.eq_ignore_ascii_case("pet") => RegionKind::Pet,
+        t if t.eq_ignore_ascii_case("focus") => RegionKind::Focus,
+        t if t.eq_ignore_ascii_case("barcode") => RegionKind::BarCode,
+        t => RegionKind::Other(t.to_string()),
+    };
+    Some(Region { rect, kind, name, description })
+}
+
 fn fmt_gps_coord(v: f64, pos: char, neg: char) -> String {
     let a = v.abs();
     let d = a.trunc();
@@ -470,6 +542,7 @@ pub fn parse_xmp(s: &str) -> Result<XmpData, XmpError> {
         let altitude = num("exif:GPSAltitude").map(|a| if first("exif:GPSAltitudeRef").as_deref() == Some("1") { -a } else { a });
         m.gps = Some(Gps { latitude: lat, longitude: lon, altitude });
     }
+    m.regions = values.get("mwg-rs:Regions").map(parse_regions).unwrap_or_default();
     let lc_settings = props.get("lc:settings").and_then(|v| v.first()).cloned();
     Ok(XmpData { metadata: m, lc_settings, properties: props, values })
 }
@@ -610,6 +683,9 @@ mod tests {
 
     fn full() -> Metadata {
         Metadata {
+            // write_xmp doesn't emit regions yet (read-only interchange; see docs/xmp-interop.md), so the
+            // roundtrip fixture must leave this empty or `roundtrip_all_fields` can't round-trip it.
+            regions: Vec::new(),
             make: Some("Maker & Sons".into()),
             model: Some("X <1>".into()),
             serial_number: Some("SN1".into()),
@@ -764,4 +840,204 @@ mod tests {
         assert_eq!(parse_gps_coord("é"), None);
         assert_eq!(fmt_gps_coord(-45.51, 'N', 'S'), "45,30.600000S");
     }
+
+    /// MWG Region Guidelines v2.0, element form (`rdf:parseType="Resource"`, self-closing `Area`) — how
+    /// Lightroom typically writes it. One named face, one untyped/unnamed region (still usable), one
+    /// region with a description. `AppliedToDimensions` is present but irrelevant: normalized areas
+    /// (the default, and the only unit real files use) don't need it.
+    #[test]
+    fn mwg_regions_element_form() {
+        let x = r#"<x:xmpmeta xmlns:x="adobe:ns:meta/"><rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#">
+            <rdf:Description rdf:about=""
+                xmlns:mwg-rs="http://www.metadataworkinggroup.com/schemas/regions/"
+                xmlns:stArea="http://ns.adobe.com/xmp/sType/Area#"
+                xmlns:stDim="http://ns.adobe.com/xap/1.0/sType/Dimensions#">
+              <mwg-rs:Regions rdf:parseType="Resource">
+                <mwg-rs:AppliedToDimensions rdf:parseType="Resource" stDim:w="4000" stDim:h="3000" stDim:unit="pixel"/>
+                <mwg-rs:RegionList>
+                  <rdf:Bag>
+                    <rdf:li rdf:parseType="Resource">
+                      <mwg-rs:Area rdf:parseType="Resource" stArea:x="0.5" stArea:y="0.4" stArea:w="0.2" stArea:h="0.3" stArea:unit="normalized"/>
+                      <mwg-rs:Name>Jane Doe</mwg-rs:Name>
+                      <mwg-rs:Type>Face</mwg-rs:Type>
+                    </rdf:li>
+                    <rdf:li rdf:parseType="Resource">
+                      <mwg-rs:Area rdf:parseType="Resource" stArea:x="0.1" stArea:y="0.1" stArea:w="0.05" stArea:h="0.05" stArea:unit="normalized"/>
+                    </rdf:li>
+                    <rdf:li rdf:parseType="Resource">
+                      <mwg-rs:Area rdf:parseType="Resource" stArea:x="0.8" stArea:y="0.2" stArea:w="0.1" stArea:h="0.1" stArea:unit="normalized"/>
+                      <mwg-rs:Type>Pet</mwg-rs:Type>
+                      <mwg-rs:Name>Rex</mwg-rs:Name>
+                      <mwg-rs:Description>Good boy</mwg-rs:Description>
+                    </rdf:li>
+                  </rdf:Bag>
+                </mwg-rs:RegionList>
+              </mwg-rs:Regions>
+            </rdf:Description></rdf:RDF></x:xmpmeta>"#;
+        let regions = parse_xmp(x).unwrap().metadata.regions;
+        assert_eq!(regions.len(), 3, "{regions:?}");
+
+        assert_eq!(regions[0].kind, RegionKind::Face);
+        assert_eq!(regions[0].name.as_deref(), Some("Jane Doe"));
+        assert_eq!(regions[0].description, None);
+        let r = regions[0].rect;
+        assert!((r.x0 - 0.4).abs() < 1e-9 && (r.x1 - 0.6).abs() < 1e-9, "{r:?}");
+        assert!((r.y0 - 0.25).abs() < 1e-9 && (r.y1 - 0.55).abs() < 1e-9, "{r:?}");
+
+        // No mwg-rs:Type or mwg-rs:Name at all: still a usable region, kind falls back to `Other("")`.
+        assert_eq!(regions[1].kind, RegionKind::Other(String::new()));
+        assert_eq!(regions[1].name, None);
+
+        assert_eq!(regions[2].kind, RegionKind::Pet);
+        assert_eq!(regions[2].name.as_deref(), Some("Rex"));
+        assert_eq!(regions[2].description.as_deref(), Some("Good boy"));
+    }
+
+    /// Lightroom Classic writes a rotated photo's (Exif orientation 3 / 6 / 8) box in the sensor's frame
+    /// and records the orientation as `mwg-rs:Rotation` (±π / −π/2 / +π/2); the reader returns the
+    /// upright frame.
+    #[test]
+    fn mwg_regions_quarter_turn_rotation_is_mapped_to_the_upright_frame() {
+        let x = r#"<x:xmpmeta xmlns:x="adobe:ns:meta/"><rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#">
+            <rdf:Description rdf:about=""
+                xmlns:mwg-rs="http://www.metadataworkinggroup.com/schemas/regions/"
+                xmlns:stArea="http://ns.adobe.com/xmp/sType/Area#">
+              <mwg-rs:Regions rdf:parseType="Resource">
+                <mwg-rs:RegionList>
+                  <rdf:Bag>
+                    <rdf:li rdf:parseType="Resource" mwg-rs:Rotation="-1.57080" mwg-rs:Type="Face">
+                      <mwg-rs:Area rdf:parseType="Resource" stArea:x="0.3" stArea:y="0.4" stArea:w="0.2" stArea:h="0.3"/>
+                    </rdf:li>
+                    <rdf:li rdf:parseType="Resource" mwg-rs:Rotation="1.57080" mwg-rs:Type="Face">
+                      <mwg-rs:Area rdf:parseType="Resource" stArea:x="0.3" stArea:y="0.4" stArea:w="0.2" stArea:h="0.3"/>
+                    </rdf:li>
+                    <rdf:li rdf:parseType="Resource" mwg-rs:Rotation="0.00000" mwg-rs:Type="Face">
+                      <mwg-rs:Area rdf:parseType="Resource" stArea:x="0.3" stArea:y="0.4" stArea:w="0.2" stArea:h="0.3"/>
+                    </rdf:li>
+                    <rdf:li rdf:parseType="Resource" mwg-rs:Rotation="3.14159" mwg-rs:Type="Face">
+                      <mwg-rs:Area rdf:parseType="Resource" stArea:x="0.3" stArea:y="0.4" stArea:w="0.2" stArea:h="0.3"/>
+                    </rdf:li>
+                    <rdf:li rdf:parseType="Resource" mwg-rs:Rotation="-3.14159" mwg-rs:Type="Face">
+                      <mwg-rs:Area rdf:parseType="Resource" stArea:x="0.3" stArea:y="0.4" stArea:w="0.2" stArea:h="0.3"/>
+                    </rdf:li>
+                  </rdf:Bag>
+                </mwg-rs:RegionList>
+              </mwg-rs:Regions>
+            </rdf:Description></rdf:RDF></x:xmpmeta>"#;
+        let regions = parse_xmp(x).unwrap().metadata.regions;
+        assert_eq!(regions.len(), 5, "{regions:?}");
+        let near = |r: Rect, b: [f64; 4]| [r.x0 - b[0], r.y0 - b[1], r.x1 - b[2], r.y1 - b[3]].iter().all(|d| d.abs() < 1e-9);
+        assert!(near(regions[0].rect, [0.45, 0.2, 0.75, 0.4]), "−π/2 (orientation 6): {:?}", regions[0].rect);
+        assert!(near(regions[1].rect, [0.25, 0.6, 0.55, 0.8]), "+π/2 (orientation 8): {:?}", regions[1].rect);
+        assert!(near(regions[2].rect, [0.2, 0.25, 0.4, 0.55]), "0 is untouched: {:?}", regions[2].rect);
+        assert!(near(regions[3].rect, [0.6, 0.45, 0.8, 0.75]), "π (orientation 3): {:?}", regions[3].rect);
+        assert!(near(regions[4].rect, [0.6, 0.45, 0.8, 0.75]), "−π (orientation 3): {:?}", regions[4].rect);
+    }
+
+    /// A second, differently-shaped encoding: each region is its own `rdf:Description` (rather than an
+    /// `rdf:li rdf:parseType="Resource"`), `mwg-rs:Type` as an attribute instead of an element, and an
+    /// unrecognised `mwg-rs:Type` value kept verbatim.
+    #[test]
+    fn mwg_regions_attribute_form_and_unknown_type() {
+        let x = r#"<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#">
+            <rdf:Description rdf:about=""
+                xmlns:mwg-rs="http://www.metadataworkinggroup.com/schemas/regions/"
+                xmlns:stArea="http://ns.adobe.com/xmp/sType/Area#">
+              <mwg-rs:Regions rdf:parseType="Resource">
+                <mwg-rs:RegionList>
+                  <rdf:Bag>
+                    <rdf:li>
+                      <rdf:Description mwg-rs:Type="BarCode">
+                        <mwg-rs:Area stArea:x="0.3" stArea:y="0.3" stArea:w="0.1" stArea:h="0.1"/>
+                      </rdf:Description>
+                    </rdf:li>
+                    <rdf:li>
+                      <rdf:Description mwg-rs:Type="Sticker">
+                        <mwg-rs:Area stArea:x="0.6" stArea:y="0.6" stArea:w="0.1" stArea:h="0.1"/>
+                      </rdf:Description>
+                    </rdf:li>
+                  </rdf:Bag>
+                </mwg-rs:RegionList>
+              </mwg-rs:Regions>
+            </rdf:Description></rdf:RDF>"#;
+        let regions = parse_xmp(x).unwrap().metadata.regions;
+        assert_eq!(regions.len(), 2, "{regions:?}");
+        assert_eq!(regions[0].kind, RegionKind::BarCode);
+        assert_eq!(regions[1].kind, RegionKind::Other("Sticker".to_string()));
+    }
+
+    /// Hostile/malformed regions are dropped individually, never panic, and never poison the rest of
+    /// the list: missing Area, non-finite or absurd numbers, zero/negative size, and a pixel-unit area
+    /// with no `AppliedToDimensions` to convert it (so it can't be stored as a nonsense fraction).
+    #[test]
+    fn mwg_regions_hostile_inputs_are_dropped_not_panicking() {
+        let x = r#"<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#">
+            <rdf:Description rdf:about=""
+                xmlns:mwg-rs="http://www.metadataworkinggroup.com/schemas/regions/"
+                xmlns:stArea="http://ns.adobe.com/xmp/sType/Area#">
+              <mwg-rs:Regions rdf:parseType="Resource">
+                <mwg-rs:RegionList>
+                  <rdf:Bag>
+                    <rdf:li rdf:parseType="Resource"><mwg-rs:Name>No Area</mwg-rs:Name></rdf:li>
+                    <rdf:li rdf:parseType="Resource"><mwg-rs:Area rdf:parseType="Resource" stArea:x="NaN" stArea:y="0.1" stArea:w="0.1" stArea:h="0.1"/></rdf:li>
+                    <rdf:li rdf:parseType="Resource"><mwg-rs:Area rdf:parseType="Resource" stArea:x="1e300" stArea:y="0.1" stArea:w="0.1" stArea:h="0.1"/></rdf:li>
+                    <rdf:li rdf:parseType="Resource"><mwg-rs:Area rdf:parseType="Resource" stArea:x="0.5" stArea:y="0.5" stArea:w="0" stArea:h="0.1"/></rdf:li>
+                    <rdf:li rdf:parseType="Resource"><mwg-rs:Area rdf:parseType="Resource" stArea:x="0.5" stArea:y="0.5" stArea:w="-0.1" stArea:h="0.1"/></rdf:li>
+                    <rdf:li rdf:parseType="Resource"><mwg-rs:Area rdf:parseType="Resource" stArea:x="100" stArea:y="100" stArea:w="50" stArea:h="50" stArea:unit="pixel"/></rdf:li>
+                    <rdf:li rdf:parseType="Resource"><mwg-rs:Area rdf:parseType="Resource" stArea:x="0.5" stArea:y="0.5" stArea:w="0.2" stArea:h="0.2"/><mwg-rs:Type>Face</mwg-rs:Type></rdf:li>
+                  </rdf:Bag>
+                </mwg-rs:RegionList>
+              </mwg-rs:Regions>
+            </rdf:Description></rdf:RDF>"#;
+        let regions = parse_xmp(x).unwrap().metadata.regions;
+        assert_eq!(regions.len(), 1, "only the last, well-formed region should survive: {regions:?}");
+        assert_eq!(regions[0].kind, RegionKind::Face);
+    }
+
+    /// Regions are clipped to the photo frame, and ones that miss the photo entirely are dropped: a
+    /// hostile sidecar can't park a box at x=1e5 (or a 1e5-wide one) that the loupe or the People view
+    /// would then draw or crop far outside the image.
+    #[test]
+    fn mwg_regions_are_clipped_to_the_frame_and_off_photo_ones_dropped() {
+        let x = r#"<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#">
+            <rdf:Description rdf:about=""
+                xmlns:mwg-rs="http://www.metadataworkinggroup.com/schemas/regions/"
+                xmlns:stArea="http://ns.adobe.com/xmp/sType/Area#">
+              <mwg-rs:Regions rdf:parseType="Resource">
+                <mwg-rs:RegionList>
+                  <rdf:Bag>
+                    <rdf:li rdf:parseType="Resource"><mwg-rs:Area rdf:parseType="Resource" stArea:x="1e5" stArea:y="0.5" stArea:w="0.1" stArea:h="0.1"/><mwg-rs:Name>Far right</mwg-rs:Name></rdf:li>
+                    <rdf:li rdf:parseType="Resource"><mwg-rs:Area rdf:parseType="Resource" stArea:x="-3" stArea:y="-3" stArea:w="0.5" stArea:h="0.5"/><mwg-rs:Name>Far left</mwg-rs:Name></rdf:li>
+                    <rdf:li rdf:parseType="Resource"><mwg-rs:Area rdf:parseType="Resource" stArea:x="1.2" stArea:y="0.5" stArea:w="0.2" stArea:h="0.2"/><mwg-rs:Name>Touching edge</mwg-rs:Name></rdf:li>
+                    <rdf:li rdf:parseType="Resource"><mwg-rs:Area rdf:parseType="Resource" stArea:x="0.5" stArea:y="0.5" stArea:w="1e5" stArea:h="1e5"/><mwg-rs:Name>Huge</mwg-rs:Name></rdf:li>
+                    <rdf:li rdf:parseType="Resource"><mwg-rs:Area rdf:parseType="Resource" stArea:x="0.95" stArea:y="0.05" stArea:w="0.2" stArea:h="0.2"/><mwg-rs:Name>Corner</mwg-rs:Name></rdf:li>
+                  </rdf:Bag>
+                </mwg-rs:RegionList>
+              </mwg-rs:Regions>
+            </rdf:Description></rdf:RDF>"#;
+        let regions = parse_xmp(x).unwrap().metadata.regions;
+        let names: Vec<_> = regions.iter().map(|r| r.name.as_deref().unwrap_or("")).collect();
+        assert_eq!(names, ["Huge", "Corner"], "{regions:?}");
+        for r in &regions {
+            let q = r.rect;
+            assert!(q.x0 >= 0.0 && q.y0 >= 0.0 && q.x1 <= 1.0 && q.y1 <= 1.0 && !q.is_empty(), "{q:?}");
+        }
+        assert_eq!(regions[0].rect, Rect::UNIT);
+        let c = regions[1].rect;
+        assert!((c.x0 - 0.85).abs() < 1e-9 && c.x1 == 1.0 && c.y0 == 0.0 && (c.y1 - 0.15).abs() < 1e-9, "{c:?}");
+    }
+
+    /// `extract()`'s precedence (EXIF/IPTC never carry regions; XMP is read and filled in like keywords).
+    #[test]
+    fn regions_merge_like_keywords() {
+        let with_region = Region { rect: Rect::from_center(Point::new(0.5, 0.5), 0.2, 0.2), kind: RegionKind::Face, name: None, description: None };
+        let mut a = Metadata::default();
+        let b = Metadata { regions: vec![with_region.clone()], ..Default::default() };
+        a.fill_missing(&b);
+        assert_eq!(a.regions, vec![with_region.clone()]);
+
+        let mut a = Metadata::default();
+        a.overlay_user_fields(&b);
+        assert_eq!(a.regions, vec![with_region]);
+    }
 }

crates/pipeline/src/finish.rs

@@ -221,7 +221,9 @@ impl FinishParams {
         FinishParams {
             calib: if calibration { crate::colorops::calibration_matrix(&s.calibration) } else { None },
             shadow_tint: if calibration { (s.calibration.shadows_tint / 100.0) as f32 } else { 0.0 },
-            tone: if info.raw {
+            tone: if let Some(curve) = info.camera_tone.as_ref().filter(|_| info.raw) {
+                ToneMap::camera(curve, s.light.contrast, s.light.whites, s.light.blacks)
+            } else if info.raw {
                 ToneMap::new(s.light.contrast, s.light.whites, s.light.blacks)
             } else {
                 ToneMap::display(s.light.contrast, s.light.whites, s.light.blacks)
@@ -481,6 +483,10 @@ pub(crate) fn finish_with<T: Copy + Default + Send>(
             let yl = luminance_2020(c);
             let o = tone.apply(yl);
             let mut d = if yl > 1e-9 { c.map(|v| v * o / yl) } else { [0.0; 3] };
+            let k = tone.chroma_scale(o);
+            if k != 1.0 {
+                d = d.map(|v| o + (v - o) * k);
+            }
             let mx = d[0].max(d[1]).max(d[2]);
             if mx > 1.0 {
                 let t = ((mx - 1.0) / (mx - o).max(1e-6)).clamp(0.0, 1.0);

crates/pipeline/src/lib.rs

@@ -64,11 +64,14 @@ pub struct SourceInfo {
     pub raw: bool,
     pub as_shot_temp: f64,
     pub as_shot_tint: f64,
+    /// No measured camera illuminant: WB adjustments are relative to the camera's rendered look.
+    pub relative_wb: bool,
+    pub camera_tone: Option<tone::CameraTone>,
 }
 
 impl Default for SourceInfo {
     fn default() -> Self {
-        Self { raw: false, as_shot_temp: 6500.0, as_shot_tint: 0.0, lens: None }
+        Self { raw: false, as_shot_temp: 6500.0, as_shot_tint: 0.0, lens: None, relative_wb: false, camera_tone: None }
     }
 }
 

crates/pipeline/src/local.rs

@@ -61,7 +61,7 @@ pub fn effective_wb(info: &SourceInfo, s: &DevelopSettings) -> (f64, f64) {
     use lightcraft_develop::WbMode;
     match s.wb.mode {
         WbMode::AsShot => (info.as_shot_temp, info.as_shot_tint),
-        m if info.raw => m.preset().unwrap_or((s.wb.temp, s.wb.tint)),
+        m if info.raw && !info.relative_wb => m.preset().unwrap_or((s.wb.temp, s.wb.tint)),
         _ => (s.wb.temp, s.wb.tint),
     }
 }

crates/pipeline/src/masks.rs

@@ -3,7 +3,7 @@
 //! Shapes are defined in normalized oriented-image coordinates; sizes are in "long-edge units".
 //! Components combine with Add (max), Subtract (a·(1−c)) and Intersect (a·c).
 
-use lightcraft_develop::{BrushStroke, LocalAdjustments, Mask, MaskOp, MaskShape};
+use lightcraft_develop::{BrushStroke, LocalAdjustments, Mask, MaskOp, MaskShape, SegMask};
 use lightcraft_geom::Point;
 use lightcraft_raster::{Plane, Rgb32f};
 
@@ -153,6 +153,19 @@ pub fn shape_alpha(shape: &MaskShape, frame: &Frame, w: usize, h: usize, img: &R
             }
             smooth_plane(&mut out, 0.01 * frame_px(frame, w));
         }
+        MaskShape::Object { seg, detail, edge, .. } | MaskShape::Prompt { seg, detail, edge, .. } if seg.is_some() || !detail.is_empty() => {
+            // Edge: below 0 a steeper transition (up to 8× the logits), above 0 feathered (up to
+            // 2 % of the long edge, so previews and exports match)
+            let e = (*edge / 100.0).clamp(-1.0, 1.0) as f32;
+            let gain = if e < 0.0 { 1.0 - 7.0 * e } else { 1.0 };
+            sample_seg(seg.as_ref(), detail, gain, frame, w, h, &mut out);
+            if e > 0.0 {
+                smooth_plane(&mut out, e * 0.02 * frame_px(frame, w));
+            }
+        }
+        // not computed yet (no clicks, or a build without the model): nothing selected
+        MaskShape::Object { hint, .. } if hint.is_empty() => {}
+        MaskShape::Prompt { .. } => {}
         MaskShape::Subject | MaskShape::Object { .. } | MaskShape::People { .. } => {
             // Saliency heuristic: centre-weighted local contrast (replaced by the segmenter in M12).
             let m = frame.out_to_norm(w, h);
@@ -176,6 +189,61 @@ pub fn shape_alpha(shape: &MaskShape, frame: &Frame, w: usize, h: usize, img: &R
     out
 }
 
+/// A decoded [`SegMask`]: its logits and the normalized rectangle they cover.
+struct SegGrid {
+    logits: Vec<f32>,
+    side: usize,
+    r: [f64; 4],
+}
+
+impl SegGrid {
+    fn new(seg: &SegMask) -> Option<SegGrid> {
+        Some(SegGrid { logits: seg.logits()?, side: seg.side as usize, r: seg.bounds()? })
+    }
+
+    fn contains(&self, n: Point) -> bool {
+        n.x >= self.r[0] && n.x <= self.r[2] && n.y >= self.r[1] && n.y <= self.r[3]
+    }
+
+    /// The bilinearly sampled logit at normalized image point `n` (cell centres at
+    /// `(i + 0.5) / side` of the rectangle).
+    fn logit(&self, n: Point) -> f32 {
+        let side = self.side;
+        let at = |x: usize, y: usize| self.logits.get(y.min(side - 1) * side + x.min(side - 1)).copied().unwrap_or(-16.0);
+        let u = (n.x - self.r[0]) / (self.r[2] - self.r[0]);
+        let v = (n.y - self.r[1]) / (self.r[3] - self.r[1]);
+        let (fx, fy) = ((u * side as f64 - 0.5) as f32, (v * side as f64 - 0.5) as f32);
+        let (fx, fy) = (fx.clamp(0.0, (side - 1) as f32), fy.clamp(0.0, (side - 1) as f32));
+        let (x0, y0) = (fx.floor() as usize, fy.floor() as usize);
+        let (tx, ty) = (fx - x0 as f32, fy - y0 as f32);
+        let top = at(x0, y0) * (1.0 - tx) + at(x0 + 1, y0) * tx;
+        let bot = at(x0, y0 + 1) * (1.0 - tx) + at(x0 + 1, y0 + 1) * tx;
+        top * (1.0 - ty) + bot * ty
+    }
+}
+
+/// Stored model segmentations at each output pixel: the zoomed-in `detail` passes inside
+/// their rectangles (the highest of them where they overlap), the whole-photo `seg`
+/// elsewhere; the logit (times `gain`: > 1 is a harder edge) through a sigmoid. Damaged
+/// data selects nothing.
+fn sample_seg(seg: Option<&SegMask>, detail: &[SegMask], gain: f32, frame: &Frame, w: usize, h: usize, out: &mut Plane) {
+    let coarse = seg.and_then(SegGrid::new);
+    // (capped: a hostile document can hold many)
+    let patches: Vec<SegGrid> = detail.iter().take(lightcraft_develop::segmask::MAX_DETAIL).filter_map(SegGrid::new).collect();
+    if coarse.is_none() && patches.is_empty() {
+        return;
+    }
+    let m = frame.out_to_norm(w, h);
+    for_rows(&mut out.data, w, |y, row| {
+        for (x, v) in row.iter_mut().enumerate() {
+            let n = m.apply(Point::new(x as f64 + 0.5, y as f64 + 0.5));
+            let fine = patches.iter().filter(|p| p.contains(n)).map(|p| p.logit(n)).reduce(f32::max);
+            let l = fine.or_else(|| coarse.as_ref().map(|c| c.logit(n))).unwrap_or(-16.0);
+            *v = 1.0 / (1.0 + (-l * gain).exp());
+        }
+    });
+}
+
 fn frame_px(frame: &Frame, w: usize) -> f32 {
     frame.px_per_long(w) as f32
 }
@@ -356,6 +424,93 @@ mod tests {
         assert!((a.get(50, 25) - 0.5).abs() < 0.05);
     }
 
+    #[test]
+    fn stored_segmentations_render_at_any_size_and_follow_the_crop() {
+        // the left half selected, on a 16² logit grid
+        let side = 16;
+        let logits: Vec<f32> = (0..side * side).map(|i| if i % side < side / 2 { 12.0 } else { -12.0 }).collect();
+        let seg = SegMask::from_logits(side, &logits);
+        for shape in [
+            MaskShape::Object { hint: vec![Point::new(0.25, 0.5)], exclude: vec![], seg: Some(seg.clone()), detail: vec![], edge: 0.0 },
+            MaskShape::Prompt { text: "left".into(), seg: Some(seg.clone()), detail: vec![], edge: 0.0 },
+        ] {
+            for (w, h) in [(40, 20), (400, 200)] {
+                let a = shape_alpha(&shape, &frame(w, h), w, h, &Rgb32f::new(w, h), &Plane::new(w, h), 0.0);
+                assert!(a.get(1, h / 2) > 0.99 && a.get(w - 2, h / 2) < 0.01, "{w}×{h}");
+                if w >= 400 {
+                    let soft = (0..w).filter(|x| (0.05..0.95).contains(&a.get(*x, h / 2))).count();
+                    assert!((2..30).contains(&soft), "an anti-aliased edge, not a ramp: {soft} px");
+                }
+            }
+        }
+        // cropped to the right half: nothing left selected
+        let mut d = DevelopSettings::default();
+        d.crop.geometry.rect = lightcraft_geom::Rect::from_center(Point::new(0.75, 0.5), 0.5, 1.0);
+        let f = Frame::new(40, 20, &d, true);
+        let shape = MaskShape::Prompt { text: "left".into(), seg: Some(seg), detail: vec![], edge: 0.0 };
+        let a = shape_alpha(&shape, &f, 20, 20, &Rgb32f::new(20, 20), &Plane::new(20, 20), 0.0);
+        assert!(a.data.iter().all(|v| *v < 0.05));
+    }
+
+    #[test]
+    fn detail_patches_replace_the_coarse_mask_inside_their_rectangle() {
+        // coarse: nothing; a patch over the right half selects its own left half (x 0.5..0.75)
+        let coarse = SegMask::from_logits(4, &[-12.0; 16]);
+        let side = 16;
+        let l: Vec<f32> = (0..side * side).map(|i| if i % side < side / 2 { 12.0 } else { -12.0 }).collect();
+        let patch = SegMask::from_logits_in(side, &l, [0.5, 0.0, 1.0, 1.0]);
+        let shape = MaskShape::Object { hint: vec![Point::new(0.6, 0.5)], exclude: vec![], seg: Some(coarse), detail: vec![patch], edge: 0.0 };
+        let (w, h) = (200, 100);
+        let a = shape_alpha(&shape, &frame(w, h), w, h, &Rgb32f::new(w, h), &Plane::new(w, h), 0.0);
+        assert!(a.get(20, 50) < 0.01, "outside the patch: the coarse mask");
+        assert!(a.get(120, 50) > 0.99, "inside the patch, its selected half");
+        assert!(a.get(190, 50) < 0.01, "inside the patch, its unselected half");
+    }
+
+    #[test]
+    fn a_hostile_number_of_detail_patches_is_capped() {
+        // built in memory (a deserialized document is capped already): only the first
+        // MAX_DETAIL are decoded and sampled, so this needs 4 × 4 MB, not 20 000 × 4 MB
+        let side = 1024;
+        let l: Vec<f32> = vec![12.0; side * side];
+        let patch = SegMask::from_logits_in(side, &l, [0.0, 0.0, 0.5, 1.0]);
+        let shape = MaskShape::Object { hint: vec![Point::new(0.2, 0.5)], exclude: vec![], seg: None, detail: vec![patch; 20_000], edge: 0.0 };
+        let (w, h) = (64, 32);
+        let t = std::time::Instant::now();
+        let a = shape_alpha(&shape, &frame(w, h), w, h, &Rgb32f::new(w, h), &Plane::new(w, h), 0.0);
+        assert!(a.get(5, 16) > 0.99 && a.get(60, 16) < 0.01);
+        assert!(t.elapsed() < std::time::Duration::from_secs(20), "{:?}", t.elapsed());
+    }
+
+    #[test]
+    fn the_edge_setting_hardens_or_feathers_the_transition() {
+        let side = 16;
+        let l: Vec<f32> = (0..side * side).map(|i| ((i % side) as f32 - 7.5) * -0.6).collect(); // a gentle ramp
+        let seg = SegMask::from_logits(side, &l);
+        let (w, h) = (400, 40);
+        let soft_px = |edge: f64| {
+            let shape = MaskShape::Prompt { text: "x".into(), seg: Some(seg.clone()), detail: vec![], edge };
+            let a = shape_alpha(&shape, &frame(w, h), w, h, &Rgb32f::new(w, h), &Plane::new(w, h), 0.0);
+            assert!(a.get(2, h / 2) > 0.9 && a.get(w - 3, h / 2) < 0.1, "still the same selection at {edge}");
+            (0..w).filter(|x| (0.1..0.9).contains(&a.get(*x, h / 2))).count()
+        };
+        let (hard, plain, soft) = (soft_px(-100.0), soft_px(0.0), soft_px(100.0));
+        assert!(hard < plain && plain < soft, "transition widths {hard} < {plain} < {soft}");
+    }
+
+    #[test]
+    fn ai_shapes_without_a_segmentation_select_nothing() {
+        let f = frame(30, 30);
+        let (img, l) = (Rgb32f::new(30, 30), Plane::new(30, 30));
+        for shape in [
+            MaskShape::Object { hint: vec![], exclude: vec![], seg: None, detail: vec![], edge: 0.0 },
+            MaskShape::Prompt { text: "sky".into(), seg: None, detail: vec![], edge: 0.0 },
+            MaskShape::Prompt { text: "sky".into(), seg: Some(SegMask { side: 4, data: "damaged!".into(), rect: None }), detail: vec![], edge: 0.0 },
+        ] {
+            assert!(shape_alpha(&shape, &f, 30, 30, &img, &l, 0.0).data.iter().all(|v| *v == 0.0));
+        }
+    }
+
     #[test]
     fn radial_inside_and_invert() {
         let f = frame(100, 100);

crates/pipeline/src/tone.rs

@@ -13,13 +13,99 @@ pub const GREY: f32 = 0.18;
 pub const LUT_MIN_EV: f32 = -14.0;
 pub const LUT_MAX_EV: f32 = 10.0;
 pub const LUT_N: usize = 4096;
+/// Nodes of a camera chroma curve, evenly spaced over display luminance 0..=1.
+pub const CHROMA_N: usize = 8;
+const NO_CHROMA: [f32; CHROMA_N] = [1.0; CHROMA_N];
+
+/// A file-local camera look, fitted independently of the scene-linear colour transform.
+/// Knots are scene/display-linear luminance pairs. Keeping this in the finish stage preserves
+/// RAW exposure and highlight headroom; it is never baked into the decoded sensor pixels.
+/// `chroma` scales colourfulness by display luminance after the curve (a camera's per-channel
+/// curve saturates shadows and bleaches highlights toward white, which a luminance curve can't).
+#[derive(Clone, Copy, Debug, PartialEq, serde::Serialize)]
+pub struct CameraTone {
+    knots: [[f32; 2]; 32],
+    chroma: [f32; CHROMA_N],
+}
+
+impl<'de> serde::Deserialize<'de> for CameraTone {
+    fn deserialize<D: serde::Deserializer<'de>>(d: D) -> Result<Self, D::Error> {
+        #[derive(serde::Deserialize)]
+        struct Wire {
+            knots: [[f32; 2]; 32],
+            // absent in smart previews written before the chroma curve existed
+            #[serde(default)]
+            chroma: Option<[f32; CHROMA_N]>,
+        }
+        let w = Wire::deserialize(d)?;
+        let tone = Self::new(w.knots).ok_or_else(|| serde::de::Error::custom("invalid camera tone curve"))?;
+        match w.chroma {
+            Some(c) => tone.with_chroma(c).ok_or_else(|| serde::de::Error::custom("invalid camera chroma curve")),
+            None => Ok(tone),
+        }
+    }
+}
+
+impl CameraTone {
+    pub fn new(knots: [[f32; 2]; 32]) -> Option<Self> {
+        let mut previous = [0.0, 0.0];
+        for p in knots {
+            if !p.iter().all(|v| v.is_finite()) || p[0] <= previous[0] || p[1] < previous[1] || p[1] >= 1.0 {
+                return None;
+            }
+            previous = p;
+        }
+        Some(Self { knots, chroma: NO_CHROMA })
+    }
+
+    /// The curve with chroma scales at display luminance 0, 1/7 … 1 (each finite, 0..=4).
+    pub fn with_chroma(self, chroma: [f32; CHROMA_N]) -> Option<Self> {
+        chroma.iter().all(|k| k.is_finite() && (0.0..=4.0).contains(k)).then_some(Self { chroma, ..self })
+    }
+
+    pub fn chroma(&self) -> &[f32; CHROMA_N] {
+        &self.chroma
+    }
+
+    pub fn apply(&self, y: f32) -> f32 {
+        if !y.is_finite() || y <= 0.0 {
+            return 0.0;
+        }
+        let mut previous = [0.0, 0.0];
+        for p in self.knots {
+            if y <= p[0] {
+                let t = (y - previous[0]) / (p[0] - previous[0]);
+                return previous[1] + t * (p[1] - previous[1]);
+            }
+            previous = p;
+        }
+        let a = self.knots[30];
+        let b = self.knots[31];
+        // Extend beyond observed (unclipped) highlights with a continuous, bounded shoulder.
+        let slope = ((b[1] - a[1]) / (b[0] - a[0])).clamp(0.1, 16.0);
+        1.0 - (1.0 - b[1]) * (-(y - b[0]) * slope / (1.0 - b[1]).max(0.01)).exp()
+    }
+}
 
 #[derive(Clone, Debug)]
 pub struct ToneMap {
     lut: Vec<f32>,
+    chroma: [f32; CHROMA_N],
 }
 
 impl ToneMap {
+    pub fn camera(curve: &CameraTone, contrast: f64, whites: f64, blacks: f64) -> ToneMap {
+        let adjustment = Self::display(contrast, whites, blacks);
+        let neutral = contrast == 0.0 && whites == 0.0 && blacks == 0.0;
+        let lut = (0..LUT_N)
+            .map(|i| {
+                let ev = LUT_MIN_EV + (LUT_MAX_EV - LUT_MIN_EV) * i as f32 / (LUT_N - 1) as f32;
+                let y = curve.apply(GREY * 2f32.powf(ev));
+                if neutral { y } else { adjustment.apply(y) }
+            })
+            .collect();
+        ToneMap { lut, chroma: curve.chroma }
+    }
     /// `contrast`, `whites`, `blacks` in −100..100 (Lightroom slider units).
     pub fn new(contrast: f64, whites: f64, blacks: f64) -> ToneMap {
         let c = (contrast / 100.0) as f32;
@@ -50,7 +136,7 @@ impl ToneMap {
                 o.clamp(0.0, 1.0)
             })
             .collect();
-        ToneMap { lut }
+        ToneMap { lut, chroma: NO_CHROMA }
     }
 
     /// Tone map for display-referred sources: identity at neutral settings.
@@ -84,7 +170,7 @@ impl ToneMap {
                 o.clamp(0.0, 1.0)
             })
             .collect();
-        ToneMap { lut }
+        ToneMap { lut, chroma: NO_CHROMA }
     }
 
     /// The table (`LUT_N` entries, see [`ToneMap::apply`]).
@@ -92,6 +178,24 @@ impl ToneMap {
         &self.lut
     }
 
+    /// The chroma curve (`CHROMA_N` entries, see [`ToneMap::chroma_scale`]).
+    pub fn chroma_lut(&self) -> &[f32] {
+        &self.chroma
+    }
+
+    /// Chroma scale at display luminance `o` (exactly 1 everywhere unless a camera look sets it).
+    #[inline]
+    pub fn chroma_scale(&self, o: f32) -> f32 {
+        if !o.is_finite() {
+            return 1.0;
+        }
+        let f = o.clamp(0.0, 1.0) * (CHROMA_N - 1) as f32;
+        let i = (f as usize).min(CHROMA_N - 2);
+        let t = f - i as f32;
+        let (a, b) = (self.chroma.get(i).copied().unwrap_or(1.0), self.chroma.get(i + 1).copied().unwrap_or(1.0));
+        if a == b { a } else { a + (b - a) * t }
+    }
+
     /// Scene luminance → display-linear luminance.
     #[inline]
     pub fn apply(&self, y: f32) -> f32 {
@@ -116,6 +220,62 @@ fn smooth(e0: f32, e1: f32, x: f32) -> f32 {
 mod tests {
     use super::*;
 
+    fn knots() -> [[f32; 2]; 32] {
+        std::array::from_fn(|i| {
+            let x = 0.004 * 1.18f32.powi(i as i32);
+            [x, 1.0 - (-2.0 * x).exp()]
+        })
+    }
+
+    #[test]
+    fn chroma_curve_is_identity_unless_set_and_survives_serde() {
+        let plain = CameraTone::new(knots()).unwrap();
+        let map = ToneMap::camera(&plain, 0.0, 0.0, 0.0);
+        assert!([0.0, 0.3, 0.77, 1.0, 2.0].iter().all(|o| map.chroma_scale(*o) == 1.0));
+        assert!([0.0, 0.5, 1.0].iter().all(|o| ToneMap::new(0.0, 0.0, 0.0).chroma_scale(*o) == 1.0));
+        // smart previews written before the chroma curve existed still load (identity)
+        let old = serde_json::json!({ "knots": knots() });
+        assert_eq!(serde_json::from_value::<CameraTone>(old).unwrap(), plain);
+        let tone = plain.with_chroma([1.4, 1.3, 1.1, 1.0, 0.7, 0.4, 0.25, 0.2]).unwrap();
+        let back: CameraTone = serde_json::from_value(serde_json::to_value(tone).unwrap()).unwrap();
+        assert_eq!(back, tone);
+        let map = ToneMap::camera(&tone, 0.0, 0.0, 0.0);
+        assert!((map.chroma_scale(0.0) - 1.4).abs() < 1e-6 && (map.chroma_scale(1.0) - 0.2).abs() < 1e-6);
+        assert!((map.chroma_scale(0.5 / 7.0) - 1.35).abs() < 1e-5, "interpolates between nodes");
+        assert_eq!(map.chroma_scale(f32::NAN), 1.0);
+        // hostile values are rejected, also when deserialized
+        assert!(plain.with_chroma([f32::NAN; CHROMA_N]).is_none());
+        assert!(plain.with_chroma([-1.0; CHROMA_N]).is_none());
+        let bad = serde_json::json!({ "knots": knots(), "chroma": [9.0, 1, 1, 1, 1, 1, 1, 1] });
+        assert!(serde_json::from_value::<CameraTone>(bad).is_err());
+    }
+
+    #[test]
+    fn camera_curve_preserves_black_and_extends_headroom() {
+        let knots = std::array::from_fn(|i| {
+            let x = 0.005 * 1.15f32.powi(i as i32);
+            [x, 1.0 - (-3.0 * x).exp()]
+        });
+        let curve = CameraTone::new(knots).unwrap();
+        let base = ToneMap::camera(&curve, 0.0, 0.0, 0.0);
+        assert_eq!(base.apply(0.0), 0.0);
+        assert!(base.apply(0.1) < base.apply(0.2));
+        let mut previous = 0.0;
+        for i in 0..2000 {
+            let y = 1e-6 * 1.01f32.powi(i);
+            let v = base.apply(y);
+            assert!((0.0..=1.0).contains(&v));
+            assert!(v >= previous - 1e-6);
+            previous = v;
+        }
+        assert!((base.apply(0.1) - curve.apply(0.1)).abs() < 0.001);
+        assert!(ToneMap::camera(&curve, 50.0, 0.0, 0.0).apply(0.3) > base.apply(0.3));
+        let mut invalid = knots;
+        invalid[1][0] = invalid[0][0];
+        assert!(CameraTone::new(invalid).is_none());
+        assert!(serde_json::from_value::<CameraTone>(serde_json::json!({"knots": invalid})).is_err());
+    }
+
     #[test]
     fn monotone_and_bounded() {
         for (c, w, b) in [(0.0, 0.0, 0.0), (100.0, 100.0, -100.0), (-100.0, -100.0, 100.0), (50.0, -30.0, -40.0)] {

crates/raw/src/dng.rs

@@ -1,6 +1,7 @@
 //! DNG (Adobe Digital Negative Specification 1.7): raw IFD selection, pixel data (via [`crate::tiffraw`]),
 //! linearization, black/white levels, active area, default crop, CFA description, colour tags, opcode lists.
 
+use crate::profile::{HsvTable, ProfileLook, ToneCurve};
 use crate::tiffraw::{Packing, read_image_in};
 use crate::{BlackLevel, Cfa, ColorData, Mat3, Mode, RawData, RawError, RawFormat, RawImage, Rect, Result, opcodes};
 use lightcraft_color::Xy;
@@ -45,6 +46,27 @@ pub(crate) fn color_data(ifd0: &Ifd, raw: &Ifd) -> ColorData {
         as_shot_white_xy: get(t::AS_SHOT_WHITE_XY).filter(|v| v.len() == 2 && v[0] > 0.0 && v[1] > 0.0).map(|v| Xy::new(v[0], v[1])),
         baseline_exposure: get(t::BASELINE_EXPOSURE).and_then(|v| v.first().copied()).filter(|v| v.is_finite()).unwrap_or(0.0)
             + get(t::BASELINE_EXPOSURE_OFFSET).and_then(|v| v.first().copied()).filter(|v| v.is_finite()).unwrap_or(0.0),
+        profile: profile_look(ifd0, raw),
+    }
+}
+
+/// The profile look tags (`ProfileHueSatMap*`, `ProfileLookTable*`, `ProfileToneCurve`); malformed
+/// ones are ignored. Like the colour tags, read from the raw IFD first, else IFD 0.
+pub(crate) fn profile_look(ifd0: &Ifd, raw: &Ifd) -> ProfileLook {
+    let pick = |tag: u16| if raw.contains(tag) { raw } else { ifd0 };
+    let table = |dims: u16, data: u16, enc: u16| {
+        let ifd = pick(dims);
+        let dims = ifd.u64s(dims)?;
+        let data = ifd.f64s(data)?;
+        HsvTable::from_tags(&dims, &data, ifd.u64s(enc).and_then(|v| v.first().copied()).unwrap_or(0))
+    };
+    ProfileLook {
+        hue_sat_map: [
+            table(t::PROFILE_HUE_SAT_MAP_DIMS, t::PROFILE_HUE_SAT_MAP_DATA_1, t::PROFILE_HUE_SAT_MAP_ENCODING),
+            table(t::PROFILE_HUE_SAT_MAP_DIMS, t::PROFILE_HUE_SAT_MAP_DATA_2, t::PROFILE_HUE_SAT_MAP_ENCODING),
+        ],
+        look_table: table(t::PROFILE_LOOK_TABLE_DIMS, t::PROFILE_LOOK_TABLE_DATA, t::PROFILE_LOOK_TABLE_ENCODING),
+        tone_curve: pick(t::PROFILE_TONE_CURVE).f64s(t::PROFILE_TONE_CURVE).and_then(|v| ToneCurve::from_tag(&v)),
     }
 }
 

crates/raw/src/dngwrite.rs

@@ -179,6 +179,38 @@ pub fn write_dng(raw: &RawImage, opts: &DngWriteOptions) -> Result<Vec<u8>> {
         ifd.set(t::AS_SHOT_WHITE_XY, rat_vec(&[xy.x, xy.y]));
     }
     ifd.set(t::BASELINE_EXPOSURE, Value::SRational(vec![srational(c.baseline_exposure)]));
+    // the source's own profile look travels with its data (conversions, smart previews, merges)
+    let p = &c.profile;
+    let table_tags = |ifd: &mut IfdBuilder, table: &crate::profile::HsvTable, dims: u16, enc: u16| {
+        ifd.set(dims, Value::Long(vec![table.hue_divisions as u32, table.sat_divisions as u32, table.val_divisions as u32]));
+        if table.srgb_value {
+            ifd.set(enc, Value::Long(vec![1]));
+        }
+    };
+    let flat = |table: &crate::profile::HsvTable| Value::Float(table.data.iter().flatten().copied().collect());
+    match &p.hue_sat_map {
+        [Some(a), b] => {
+            table_tags(&mut ifd, a, t::PROFILE_HUE_SAT_MAP_DIMS, t::PROFILE_HUE_SAT_MAP_ENCODING);
+            ifd.set(t::PROFILE_HUE_SAT_MAP_DATA_1, flat(a));
+            if let Some(b) =
+                b.as_ref().filter(|b| (b.hue_divisions, b.sat_divisions, b.val_divisions) == (a.hue_divisions, a.sat_divisions, a.val_divisions))
+            {
+                ifd.set(t::PROFILE_HUE_SAT_MAP_DATA_2, flat(b));
+            }
+        }
+        [None, Some(b)] => {
+            table_tags(&mut ifd, b, t::PROFILE_HUE_SAT_MAP_DIMS, t::PROFILE_HUE_SAT_MAP_ENCODING);
+            ifd.set(t::PROFILE_HUE_SAT_MAP_DATA_1, flat(b));
+        }
+        [None, None] => {}
+    }
+    if let Some(l) = &p.look_table {
+        table_tags(&mut ifd, l, t::PROFILE_LOOK_TABLE_DIMS, t::PROFILE_LOOK_TABLE_ENCODING);
+        ifd.set(t::PROFILE_LOOK_TABLE_DATA, flat(l));
+    }
+    if let Some(curve) = &p.tone_curve {
+        ifd.set(t::PROFILE_TONE_CURVE, Value::Float(curve.points.iter().flatten().copied().collect()));
+    }
     for (list, tag) in [(&raw.opcodes.list1, t::OPCODE_LIST_1), (&raw.opcodes.list2, t::OPCODE_LIST_2), (&raw.opcodes.list3, t::OPCODE_LIST_3)] {
         if !list.is_empty() {
             ifd.set(tag, Value::Undefined(opcodes::write_list(list)));

crates/raw/src/lib.rs

@@ -8,7 +8,8 @@
 //!   [`RawImage::develop`] does all of it plus `OpcodeList3` and the default crop; [`RawImage::develop_binned`]
 //!   produces the same at 1/k of the size straight from the mosaic (previews, thumbnails).
 //! - [`color`] implements the DNG colour model (dual-illuminant interpolation, forward matrices, white balance)
-//!   and produces camera → linear Rec.2020 D65 matrices.
+//!   and produces camera → linear Rec.2020 D65 matrices; [`profile`] reads and applies a DNG's own profile
+//!   look tables and tone curve.
 //!
 //! Formats: DNG (uncompressed, lossless JPEG, lossy JPEG (Smart Previews), Deflate incl. floating point, tiled/stripped, CFA and LinearRaw),
 //! Canon CR2, Nikon NEF/NRW (uncompressed, Huffman lossless / lossy compressed), Sony ARW (uncompressed, ARW2, lossless), Fujifilm RAF (uncompressed Bayer
@@ -29,6 +30,7 @@ pub mod highlight;
 pub mod ljpeg;
 pub mod opcodes;
 mod preview;
+pub mod profile;
 mod tiffraw;
 mod unpack;
 mod vendor;
@@ -393,6 +395,10 @@ pub struct ColorData {
     pub as_shot_white_xy: Option<Xy>,
     /// EV to add for a "normal" rendering (`BaselineExposure` + `BaselineExposureOffset`).
     pub baseline_exposure: f64,
+    /// The file's own camera-profile look (`ProfileHueSatMap*`, `ProfileLookTable*`,
+    /// `ProfileToneCurve`), applied by [`color`]'s users at render time.
+    #[serde(default)]
+    pub profile: profile::ProfileLook,
 }
 
 /// A decoded raw image.

crates/raw/src/preview.rs

@@ -96,10 +96,20 @@ pub fn embedded_preview(bytes: &[u8]) -> Option<Vec<u8>> {
     found.into_iter().filter(|s| is_dct_jpeg(s)).max_by_key(|s| s.len()).map(|s| trim_eoi(s).to_vec())
 }
 
+/// Canon CR3: the full-size JPEG track (see [`lightcraft_meta::cr3`]), else the `PRVW` / `THMB` boxes.
+fn cr3_preview(bytes: &[u8]) -> Option<&[u8]> {
+    let full = lightcraft_meta::cr3::parse_cr3(bytes)
+        .and_then(|c| c.tracks.iter().find(|t| t.kind == lightcraft_meta::cr3::Cr3TrackKind::Jpeg).and_then(|t| t.data));
+    if let Some(j) = full.and_then(|(at, len)| bytes.get(at..at.checked_add(len)?)).filter(|j| is_dct_jpeg(j)) {
+        return Some(j);
+    }
+    cr3_preview_boxes(bytes)
+}
+
 /// Canon CR3 (ISO base media file): the `PRVW` box (Laurent Clévy's CR3 notes; layout confirmed on a CC0
 /// sample) is `u32 size, "PRVW", u32 0, u16 ?, u16 width, u16 height, u16 ?, u32 jpeg length, JPEG`; the smaller
 /// `THMB` box has the same shape. Returns the larger valid one.
-fn cr3_preview(bytes: &[u8]) -> Option<&[u8]> {
+fn cr3_preview_boxes(bytes: &[u8]) -> Option<&[u8]> {
     let mut best: Option<&[u8]> = None;
     for tag in [b"PRVW", b"THMB"] {
         let mut from = 0;
@@ -180,4 +190,32 @@ mod tests {
             let _ = embedded_preview(&cr3[..n]);
         }
     }
+
+    /// CR3 with a full-size JPEG track: that JPEG wins over the smaller `PRVW` box.
+    #[test]
+    fn cr3_prefers_the_full_size_jpeg_track() {
+        let bx = |kind: &[u8; 4], body: &[u8]| -> Vec<u8> { [&((body.len() + 8) as u32).to_be_bytes()[..], kind, body].concat() };
+        let full = |kind: &[u8; 4], body: &[u8]| bx(kind, &[&[0u8; 4][..], body].concat());
+        let (small, big) = (fake_jpeg(300), fake_jpeg(3000));
+        let mut file = bx(b"ftyp", b"crx \0\0\0\x01crx isom");
+        let mut prvw = b"\0\0\0\0\0\x01\x06\x54\x04\x38\0\x01".to_vec();
+        prvw.extend_from_slice(&(small.len() as u32).to_be_bytes());
+        prvw.extend_from_slice(&small);
+        file.extend(bx(b"PRVW", &prvw));
+        // CRAW sample entry: 82 bytes, then a JPEG child box; one sample at `at`
+        let mut craw = vec![0u8; 82];
+        craw.extend(bx(b"JPEG", &[0; 4]));
+        let at = 2048u64;
+        let stsd = full(b"stsd", &[&1u32.to_be_bytes()[..], &bx(b"CRAW", &craw)].concat());
+        let stsz = full(b"stsz", &[0u32.to_be_bytes(), 1u32.to_be_bytes(), (big.len() as u32).to_be_bytes()].concat());
+        let co64 = full(b"co64", &[&1u32.to_be_bytes()[..], &at.to_be_bytes()].concat());
+        let trak = bx(b"trak", &bx(b"mdia", &bx(b"minf", &bx(b"stbl", &[stsd, stsz, co64].concat()))));
+        file.extend(bx(b"moov", &trak));
+        file.resize(at as usize, 0);
+        file.extend_from_slice(&big);
+        assert_eq!(embedded_preview(&file).unwrap(), big);
+        // a track pointing past the end falls back to PRVW
+        file.truncate(at as usize + 100);
+        assert_eq!(embedded_preview(&file).unwrap(), small);
+    }
 }

crates/raw/src/profile.rs

@@ -0,0 +1,387 @@
+//! DNG camera-profile look data carried by the file itself (Adobe DNG Specification 1.6/1.7,
+//! chapter 6 and the `ProfileHueSatMap*`, `ProfileLookTable*` and `ProfileToneCurve` tags).
+//!
+//! - A hue/saturation/value table holds, for a grid of (value, hue, saturation) inputs, a hue shift
+//!   in degrees, a saturation scale and a value scale (value-major, hue-middle, saturation-minor).
+//!   Hue samples are spread evenly around the circle with wrap-around, saturation and value samples
+//!   evenly over 0..=1; a dimension with one division is constant. Lookups are tri-linear.
+//! - Tables are applied in HSV of linear ProPhoto RGB (D50). With encoding 1 ("sRGB") the value
+//!   axis is indexed through the sRGB transfer curve (3D tables only).
+//! - `ProfileHueSatMapData1/2` follow the colour matrices (interpolated by the same illuminant
+//!   weight); `ProfileLookTableData` comes after exposure compensation and before any tone curve.
+//! - `ProfileToneCurve`: (input, output) pairs in linear gamma from (0, 0) to (1, 1).
+//!
+//! The data is read from the user's own file at run time; nothing here ships profile data.
+//! Values above 1.0 (highlight headroom) keep their headroom: the table's value scale only ever
+//! lowers them, so a lookup can't clip what the scene-referred pipeline still needs.
+
+use lightcraft_color::transfer::{linear_to_srgb, srgb_to_linear};
+use lightcraft_color::{D50, D65, Mat3, PROPHOTO, REC2020, bradford};
+use serde::{Deserialize, Serialize};
+
+/// Upper bound on table entries (Adobe profiles use ≤ 90 × 30 × 16; guards header-driven sizes).
+const MAX_ENTRIES: usize = 1 << 20;
+
+/// A DNG hue/saturation/value mapping table (`ProfileHueSatMapData*` / `ProfileLookTableData`).
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
+pub struct HsvTable {
+    pub hue_divisions: usize,
+    pub sat_divisions: usize,
+    pub val_divisions: usize,
+    /// `(hue shift °, saturation scale, value scale)`, value-major, hue-middle, saturation-minor.
+    pub data: Vec<[f32; 3]>,
+    /// The value axis is indexed through the sRGB encoding curve (`…Encoding` = 1).
+    pub srgb_value: bool,
+}
+
+impl HsvTable {
+    /// A table from its `…Dims` (hue, saturation, value divisions), data floats and encoding.
+    /// `None` when the dimensions are out of range, the data length doesn't match or a value is
+    /// not finite.
+    pub fn from_tags(dims: &[u64], data: &[f64], encoding: u64) -> Option<HsvTable> {
+        let [h, s, v] = <[u64; 3]>::try_from(dims).ok()?;
+        let (h, s, v) = (usize::try_from(h).ok()?, usize::try_from(s).ok()?, usize::try_from(v).ok()?);
+        if h < 1 || s < 2 || v < 1 || h > 4096 || s > 4096 || v > 4096 {
+            return None;
+        }
+        let n = h.checked_mul(s)?.checked_mul(v)?;
+        if n > MAX_ENTRIES || data.len() != n * 3 || data.iter().any(|x| !x.is_finite()) {
+            return None;
+        }
+        let data = data.as_chunks::<3>().0.iter().map(|c| [c[0] as f32, (c[1] as f32).max(0.0), (c[2] as f32).max(0.0)]).collect();
+        Some(HsvTable { hue_divisions: h, sat_divisions: s, val_divisions: v, data, srgb_value: encoding == 1 && v > 1 })
+    }
+
+    /// The entry-wise blend `g · a + (1 − g) · b` of two tables of the same shape (`None` otherwise).
+    pub fn blend(a: &HsvTable, b: &HsvTable, g: f64) -> Option<HsvTable> {
+        if (a.hue_divisions, a.sat_divisions, a.val_divisions) != (b.hue_divisions, b.sat_divisions, b.val_divisions) {
+            return None;
+        }
+        let g = g.clamp(0.0, 1.0) as f32;
+        let data = a.data.iter().zip(&b.data).map(|(x, y)| std::array::from_fn(|i| g * x[i] + (1.0 - g) * y[i])).collect();
+        Some(HsvTable { data, ..a.clone() })
+    }
+
+    fn entry(&self, v: usize, h: usize, s: usize) -> [f32; 3] {
+        self.data.get((v * self.hue_divisions + h) * self.sat_divisions + s).copied().unwrap_or([0.0, 1.0, 1.0])
+    }
+
+    /// Tri-linear lookup at hue `h` (degrees), saturation `s` and value `v` (table coordinates).
+    pub fn lookup(&self, h: f32, s: f32, v: f32) -> [f32; 3] {
+        let hf = (h.rem_euclid(360.0) / 360.0 * self.hue_divisions as f32).clamp(0.0, self.hue_divisions as f32);
+        let h0 = (hf as usize).min(self.hue_divisions - 1);
+        let h1 = (h0 + 1) % self.hue_divisions;
+        let th = (hf - h0 as f32).clamp(0.0, 1.0);
+        let axis = |x: f32, n: usize| {
+            let f = x.clamp(0.0, 1.0) * (n - 1) as f32;
+            let i0 = (f as usize).min(n.saturating_sub(2));
+            let i1 = (i0 + 1).min(n - 1);
+            (i0, i1, (f - i0 as f32).clamp(0.0, 1.0))
+        };
+        let (s0, s1, ts) = axis(s, self.sat_divisions);
+        let (v0, v1, tv) = if self.val_divisions > 1 { axis(v, self.val_divisions) } else { (0, 0, 0.0) };
+        let lerp = |a: [f32; 3], b: [f32; 3], t: f32| -> [f32; 3] { std::array::from_fn(|i| a[i] + (b[i] - a[i]) * t) };
+        let plane = |vi: usize| {
+            let lo = lerp(self.entry(vi, h0, s0), self.entry(vi, h0, s1), ts);
+            let hi = lerp(self.entry(vi, h1, s0), self.entry(vi, h1, s1), ts);
+            lerp(lo, hi, th)
+        };
+        if v0 == v1 { plane(v0) } else { lerp(plane(v0), plane(v1), tv) }
+    }
+
+    /// Apply the table to one linear ProPhoto RGB colour.
+    pub fn apply(&self, rgb: [f32; 3]) -> [f32; 3] {
+        let max = rgb[0].max(rgb[1]).max(rgb[2]);
+        if max.is_nan() || max <= 0.0 || !max.is_finite() {
+            return rgb;
+        }
+        let min = rgb[0].min(rgb[1]).min(rgb[2]);
+        let d = max - min;
+        let hue = hue_of(rgb, max, d);
+        let sat = d / max;
+        let v_index = if self.srgb_value { linear_to_srgb(max.min(1.0)) } else { max };
+        let [shift, ss, vs] = self.lookup(hue, sat, v_index);
+        // saturation and value: scaled and clipped to 1.0 (DNG chapter 6), except that inputs
+        // already above 1 (out-of-ProPhoto colours, highlight headroom) are only ever lowered.
+        let s2 = limited(sat, ss);
+        let v2 = if self.srgb_value && max <= 1.0 {
+            srgb_to_linear((linear_to_srgb(max) * vs).min(1.0))
+        } else if self.srgb_value {
+            max * srgb_to_linear(vs.min(1.0)).min(1.0)
+        } else {
+            limited(max, vs)
+        };
+        hsv_to_rgb(hue + shift, s2, v2)
+    }
+}
+
+/// `x · k` clipped to 1, for `x ≤ 1`; above 1, only scale factors below 1 apply (continuous at 1).
+fn limited(x: f32, k: f32) -> f32 {
+    if x <= 1.0 { (x * k).min(1.0) } else { x * k.min(1.0) }
+}
+
+fn hue_of(c: [f32; 3], max: f32, d: f32) -> f32 {
+    if d <= 0.0 {
+        return 0.0;
+    }
+    let h = if max == c[0] {
+        ((c[1] - c[2]) / d).rem_euclid(6.0)
+    } else if max == c[1] {
+        (c[2] - c[0]) / d + 2.0
+    } else {
+        (c[0] - c[1]) / d + 4.0
+    };
+    h * 60.0
+}
+
+/// HSV → RGB for any saturation ≥ 0 (above 1 yields negative components, the inverse of
+/// [`hue_of`] for out-of-gamut inputs).
+fn hsv_to_rgb(h: f32, s: f32, v: f32) -> [f32; 3] {
+    let hp = h.rem_euclid(360.0) / 60.0;
+    let sector = (hp as u32).min(5);
+    let f = hp - sector as f32;
+    let (p, q, t) = (v * (1.0 - s), v * (1.0 - s * f), v * (1.0 - s * (1.0 - f)));
+    match sector {
+        0 => [v, t, p],
+        1 => [q, v, p],
+        2 => [p, v, t],
+        3 => [p, q, v],
+        4 => [t, p, v],
+        _ => [v, p, q],
+    }
+}
+
+/// A DNG tone curve (`ProfileToneCurve`): linear-gamma (input, output) pairs, increasing input.
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
+pub struct ToneCurve {
+    pub points: Vec<[f32; 2]>,
+}
+
+impl ToneCurve {
+    /// From the tag's flat float pairs. `None` unless there are 2..=65536 finite pairs within
+    /// 0..=1 with strictly increasing inputs.
+    pub fn from_tag(v: &[f64]) -> Option<ToneCurve> {
+        if !v.len().is_multiple_of(2) || v.len() < 4 || v.len() > 131_072 {
+            return None;
+        }
+        let points: Vec<[f32; 2]> = v.as_chunks::<2>().0.iter().map(|p| [p[0] as f32, p[1] as f32]).collect();
+        let ok = points.iter().all(|p| p.iter().all(|x| x.is_finite() && (0.0..=1.0).contains(x))) && points.windows(2).all(|w| w[1][0] > w[0][0]);
+        ok.then_some(ToneCurve { points })
+    }
+
+    /// The curve at `x` (0..=1): monotone cubic (Fritsch–Carlson) through the samples.
+    pub fn eval(&self, x: f32) -> f32 {
+        let p = &self.points;
+        let n = p.len();
+        let x = x.clamp(p[0][0], p[n - 1][0]);
+        let i = p.partition_point(|q| q[0] <= x).clamp(1, n - 1) - 1;
+        let slope = |k: usize| (p[k + 1][1] - p[k][1]) / (p[k + 1][0] - p[k][0]);
+        let tangent = |k: usize| -> f32 {
+            if k == 0 {
+                return slope(0);
+            }
+            if k == n - 1 {
+                return slope(n - 2);
+            }
+            let (a, b) = (slope(k - 1), slope(k));
+            if a * b <= 0.0 { 0.0 } else { 2.0 / (1.0 / a + 1.0 / b) }
+        };
+        let (x0, x1) = (p[i][0], p[i + 1][0]);
+        let h = x1 - x0;
+        let t = (x - x0) / h;
+        let (t2, t3) = (t * t, t * t * t);
+        let y = (2.0 * t3 - 3.0 * t2 + 1.0) * p[i][1]
+            + (t3 - 2.0 * t2 + t) * h * tangent(i)
+            + (-2.0 * t3 + 3.0 * t2) * p[i + 1][1]
+            + (t3 - t2) * h * tangent(i + 1);
+        y.clamp(0.0, 1.0)
+    }
+}
+
+/// The DNG profile look tags of a file (all optional).
+#[derive(Clone, Debug, Default, PartialEq, Serialize, Deserialize)]
+pub struct ProfileLook {
+    /// `ProfileHueSatMapData1/2` (same shape, `ProfileHueSatMapDims`).
+    pub hue_sat_map: [Option<HsvTable>; 2],
+    /// `ProfileLookTableData`.
+    pub look_table: Option<HsvTable>,
+    /// `ProfileToneCurve`.
+    pub tone_curve: Option<ToneCurve>,
+}
+
+impl ProfileLook {
+    pub fn is_empty(&self) -> bool {
+        self.hue_sat_map.iter().all(Option::is_none) && self.look_table.is_none() && self.tone_curve.is_none()
+    }
+
+    /// The hue/saturation map for calibration-1 weight `g` (one table: used for any white).
+    pub fn hue_sat_for(&self, g: f64) -> Option<HsvTable> {
+        match &self.hue_sat_map {
+            [Some(a), Some(b)] => HsvTable::blend(a, b, g).or_else(|| Some(a.clone())),
+            [Some(a), None] | [None, Some(a)] => Some(a.clone()),
+            [None, None] => None,
+        }
+    }
+}
+
+/// The tables resolved for one white balance, applied to linear Rec.2020 D65 pixels.
+#[derive(Clone, Debug)]
+pub struct ProfileTables {
+    hue_sat: Option<HsvTable>,
+    look: Option<HsvTable>,
+    to_prophoto: [[f32; 3]; 3],
+    from_prophoto: [[f32; 3]; 3],
+}
+
+impl ProfileTables {
+    /// `None` when the profile has no hue/saturation map and no look table.
+    pub fn new(look: &ProfileLook, illuminant_weight: f64) -> Option<ProfileTables> {
+        let hue_sat = look.hue_sat_for(illuminant_weight);
+        if hue_sat.is_none() && look.look_table.is_none() {
+            return None;
+        }
+        let to: Mat3 = PROPHOTO.from_xyz().mul(&bradford(D65, D50)).mul(&REC2020.to_xyz());
+        let from = to.inverse()?;
+        Some(ProfileTables { hue_sat, look: look.look_table.clone(), to_prophoto: to.to_f32(), from_prophoto: from.to_f32() })
+    }
+
+    /// Hue/saturation map, then `gain` (exposure compensation), then the look table:
+    /// linear Rec.2020 D65 in, linear Rec.2020 D65 out.
+    #[inline]
+    pub fn apply(&self, rgb: [f32; 3], gain: f32) -> [f32; 3] {
+        let m = &self.to_prophoto;
+        let mut p: [f32; 3] = std::array::from_fn(|i| m[i][0] * rgb[0] + m[i][1] * rgb[1] + m[i][2] * rgb[2]);
+        if let Some(t) = &self.hue_sat {
+            p = t.apply(p);
+        }
+        p = p.map(|v| v * gain);
+        if let Some(t) = &self.look {
+            p = t.apply(p);
+        }
+        let m = &self.from_prophoto;
+        std::array::from_fn(|i| m[i][0] * p[0] + m[i][1] * p[1] + m[i][2] * p[2])
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn identity(h: usize, s: usize, v: usize) -> HsvTable {
+        HsvTable { hue_divisions: h, sat_divisions: s, val_divisions: v, data: vec![[0.0, 1.0, 1.0]; h * s * v], srgb_value: false }
+    }
+
+    fn close(a: [f32; 3], b: [f32; 3], tol: f32) -> bool {
+        a.iter().zip(&b).all(|(x, y)| (x - y).abs() <= tol)
+    }
+
+    #[test]
+    fn identity_table_is_identity() {
+        let t = identity(6, 3, 1);
+        for c in [[0.2, 0.5, 0.1], [0.9, 0.9, 0.9], [0.0, 0.0, 0.4], [3.0, 1.0, 0.5], [0.3, -0.05, 0.2]] {
+            assert!(close(t.apply(c), c, 1e-5), "{c:?} → {:?}", t.apply(c));
+        }
+        assert_eq!(t.apply([0.0; 3]), [0.0; 3]);
+        assert_eq!(t.apply([-1.0, -2.0, -0.5]), [-1.0, -2.0, -0.5]);
+    }
+
+    #[test]
+    fn parses_tags_and_rejects_bad_shapes() {
+        let data: Vec<f64> = (0..4).flat_map(|_| [0.0, 1.0, 1.0]).collect();
+        assert!(HsvTable::from_tags(&[2, 2, 1], &data, 0).is_some());
+        assert!(HsvTable::from_tags(&[2, 2], &data, 0).is_none());
+        assert!(HsvTable::from_tags(&[2, 1, 2], &data, 0).is_none(), "saturation needs ≥ 2 divisions");
+        assert!(HsvTable::from_tags(&[2, 2, 2], &data, 0).is_none(), "length mismatch");
+        assert!(HsvTable::from_tags(&[u64::MAX, 2, 2], &data, 0).is_none());
+        let mut nan = data.clone();
+        nan[1] = f64::NAN;
+        assert!(HsvTable::from_tags(&[2, 2, 1], &nan, 0).is_none());
+        // the sRGB encoding only applies to 3D tables
+        assert!(!HsvTable::from_tags(&[2, 2, 1], &data, 1).unwrap().srgb_value);
+    }
+
+    #[test]
+    fn saturation_scale_follows_the_table_layout() {
+        // 4 hues (0°, 90°, 180°, 270°), 2 saturations; saturation-minor: entry (h, s) at h·2 + s.
+        let mut t = identity(4, 2, 1);
+        t.data[1] = [0.0, 1.5, 1.0]; // hue 0°, saturation 1 → ×1.5
+        let red = [0.5, 0.4, 0.4]; // hue 0°, saturation 0.2
+        let out = t.apply(red);
+        // half-way along the saturation axis is ×1.1 (0.2 → 0.22 sat), value kept
+        let sat = (out[0] - out[1].min(out[2])) / out[0];
+        assert!((sat - 0.2 * 1.1).abs() < 1e-4, "{out:?}");
+        assert!((out[0] - 0.5).abs() < 1e-6);
+        // other hues are untouched (hue 180°)
+        let cyan = [0.3, 0.4, 0.4];
+        assert!(close(t.apply(cyan), cyan, 1e-6));
+        // saturation clips to 1.0
+        assert!(t.apply([1.0, 0.1, 0.1]).iter().all(|v| *v >= -1e-6));
+    }
+
+    #[test]
+    fn hue_wraps_and_value_scales() {
+        // 2 hues: entries at 0° and 180°, hue shift +20° at 0°, value ×0.5 at 180°.
+        let mut t = identity(2, 2, 1);
+        t.data = vec![[20.0, 1.0, 1.0], [20.0, 1.0, 1.0], [0.0, 1.0, 0.5], [0.0, 1.0, 0.5]];
+        // 350° sits between the last sample (180°) and the first (0° = 360°), 10/180 from 360
+        assert!((t.lookup(350.0, 0.5, 0.5)[0] - 20.0 * (170.0 / 180.0)).abs() < 1e-3);
+        assert!((t.lookup(180.0, 0.5, 0.5)[2] - 0.5).abs() < 1e-6);
+        // headroom above 1 only goes down
+        let bright = [2.0, 2.4, 2.4];
+        let out = t.apply(bright);
+        assert!((out[1] - 1.2).abs() < 1e-5, "{out:?}");
+        let mut up = identity(1, 2, 1);
+        up.data = vec![[0.0, 1.0, 2.0]; 2];
+        assert!((up.apply([0.4, 0.4, 0.4])[0] - 0.8).abs() < 1e-6);
+        assert!((up.apply([0.8, 0.8, 0.8])[0] - 1.0).abs() < 1e-6, "clipped to 1");
+        assert!((up.apply([3.0, 3.0, 3.0])[0] - 3.0).abs() < 1e-6, "headroom kept");
+    }
+
+    #[test]
+    fn value_axis_and_srgb_encoding() {
+        // 1 hue, 2 sats, 2 values: saturation ×2 at value 1 only
+        let mut t = identity(1, 2, 2);
+        t.data[3] = [0.0, 2.0, 1.0];
+        let sat = |c: [f32; 3]| (c[0] - c[2]) / c[0];
+        let dark = [0.25, 0.2, 0.2]; // V 0.25, S 0.2
+        // linear: 1/4 of the way → S scale at s=0.2: lerp(1, lerp(1,2,0.2)=1.2, 0.25) = 1.05
+        assert!((sat(t.apply(dark)) - 0.2 * 1.05).abs() < 1e-4);
+        t.srgb_value = true;
+        let k = linear_to_srgb(0.25); // ≈ 0.537
+        let want = 0.2 * (1.0 + 0.2 * k);
+        assert!((sat(t.apply(dark)) - want).abs() < 1e-4);
+    }
+
+    #[test]
+    fn blend_and_tables_round_trip_through_prophoto() {
+        let a = identity(2, 2, 1);
+        let mut b = identity(2, 2, 1);
+        b.data[1] = [10.0, 2.0, 1.0];
+        let m = HsvTable::blend(&a, &b, 0.25).unwrap();
+        assert_eq!(m.data[1], [7.5, 1.75, 1.0]);
+        assert!(HsvTable::blend(&a, &identity(3, 2, 1), 0.5).is_none());
+        let look = ProfileLook { hue_sat_map: [Some(a.clone()), None], look_table: Some(a), tone_curve: None };
+        let t = ProfileTables::new(&look, 0.5).unwrap();
+        let c = [0.3, 0.2, 0.1];
+        assert!(close(t.apply(c, 2.0), [0.6, 0.4, 0.2], 1e-4), "{:?}", t.apply(c, 2.0));
+        assert!(ProfileTables::new(&ProfileLook::default(), 0.5).is_none());
+    }
+
+    #[test]
+    fn tone_curve_interpolates_monotonically() {
+        assert!(ToneCurve::from_tag(&[0.0, 0.0]).is_none());
+        assert!(ToneCurve::from_tag(&[0.0, 0.0, 0.5, 0.6, 0.4, 0.7, 1.0, 1.0]).is_none(), "inputs must increase");
+        assert!(ToneCurve::from_tag(&[0.0, 0.0, 1.0, 1.5]).is_none());
+        let c = ToneCurve::from_tag(&[0.0, 0.0, 0.25, 0.4, 0.5, 0.7, 1.0, 1.0]).unwrap();
+        assert_eq!(c.eval(0.0), 0.0);
+        assert!((c.eval(0.25) - 0.4).abs() < 1e-6);
+        assert!((c.eval(1.0) - 1.0).abs() < 1e-6);
+        let mut last = 0.0;
+        for i in 0..=100 {
+            let y = c.eval(i as f32 / 100.0);
+            assert!(y >= last - 1e-6, "monotone at {i}");
+            last = y;
+        }
+        assert!(c.eval(0.1) > 0.1 && c.eval(0.1) < 0.4);
+    }
+}

crates/raw/src/vendor/arw.rs

@@ -14,6 +14,12 @@
 //!    a 128-bit little-endian block: 11-bit max, 11-bit min, 4-bit index of the max, 4-bit index of the min and 14
 //!    seven-bit deltas above the min, scaled by the smallest shift that fits `max − min` into 7 bits.
 //!
+//! White balance: the raw IFD's `0x7313` levels when present (bodies from about 2017 on); otherwise the
+//! `WB_RGBLevels` of the maker note's enciphered `Tag2010` block (see [`DECIPHER`] and [`TAG2010_WB`]). Without
+//! either, an ARW opened with unit multipliers, i.e. a strong green cast (issue #148). Black level: the raw IFD's
+//! `0x7310`, else the level stored in the encrypted `SR2SubIFD` (see [`SR2_BLACK_AT`]; 800 rather than the
+//! default 512 on 1″-sensor bodies such as the RX100 series), else 512 (14-bit) / 128 (12-bit).
+//!
 //! Also: uncompressed 16-bit ARW, and lossless-compressed ARW (Compression 7, ILCE-7M4 and later): LJ92 tiles whose
 //! frames hold one 2×2 CFA cell per four-component sample ([`read_quad_tiles`]). Other lossless-JPEG layouts go
 //! through the generic TIFF path.
@@ -23,7 +29,7 @@ use crate::{BlackLevel, Cfa, ColorData, Mode, OpcodeLists, RawData, RawError, Ra
 use lightcraft_geom::Orientation;
 use lightcraft_tiff::image::{Chunk, ImageInfo, Layout, chunk_bytes};
 use lightcraft_tiff::tags::{self as t, photometric};
-use lightcraft_tiff::{Ifd, Tiff};
+use lightcraft_tiff::{Ifd, Tiff, makernote};
 use rayon::prelude::*;
 
 const TONE_CURVE: u16 = 0x7010;
@@ -31,6 +37,137 @@ const BLACK_LEVEL: u16 = 0x7310;
 const WB_RGGB: u16 = 0x7313;
 const CROP_TOP_LEFT: u16 = 0x74c7;
 const CROP_SIZE: u16 = 0x74c8;
+/// Maker-note tags (ExifTool Sony tag names): the enciphered `Tag2010` block and `FullImageSize` (height, width).
+const MN_TAG2010: u16 = 0x2010;
+const MN_FULL_IMAGE_SIZE: u16 = 0xb02b;
+
+/// Inverse of Sony's maker-note byte substitution. ExifTool's Sony tag documentation states that the data of
+/// tags `0x2010`, `0x9050` and `0x94xx` "is encrypted by a simple substitution cipher" (no decoder source was
+/// consulted). The substitution, checked black-box on CC0 raw.pixls.us samples: every byte `p < 249` is stored as
+/// `p³ mod 249` (a bijection on 0..249, as 3 is coprime to φ(249) = 164) and bytes 249–255 are stored unchanged.
+/// Verified on 15 files from 13 bodies covering seven `Tag2010` layouts: the deciphered `SonyISO` field encodes
+/// the Exif ISO (`100 · 2^(16 − v/256)`), the green level is 255–256 throughout, and on the ILCE-7M3 the deciphered
+/// `WB_RGBLevels` equal the plain raw-IFD `0x7313` levels.
+const DECIPHER: [u8; 256] = {
+    let mut inv = [0u8; 256];
+    let mut p = 0usize;
+    while p < 256 {
+        let c = if p < 249 { p * p % 249 * p % 249 } else { p };
+        inv[c] = p as u8;
+        p += 1;
+    }
+    inv
+};
+
+/// `Tag2010` layouts (ExifTool "Sony Tag2010a" … "Tag2010i" tables): the models each is documented for and the
+/// byte offset of `WB_RGBLevels` (three `u16`, the as-shot white balance as R, G, B gains; Tag2010g and h share
+/// the offset). Newer bodies (Tag2010i) also write the levels in plain form in the raw IFD (`0x7313`), which takes
+/// precedence.
+const TAG2010_WB: &[(&[&str], usize)] = &[
+    (&["NEX-5N"], 4476),
+    (&["SLT-A65", "SLT-A77", "NEX-7", "NEX-VG20E"], 4480),
+    (&["SLT-A37", "SLT-A57", "NEX-F3"], 4444),
+    (&["DSC-HX10V", "DSC-HX20V", "DSC-HX200V", "DSC-TX66", "DSC-TX200V", "DSC-TX300V", "DSC-WX50", "DSC-WX100", "DSC-WX150"], 4568),
+    (
+        &[
+            "SLT-A58",
+            "SLT-A99",
+            "ILCE-3000",
+            "ILCE-3500",
+            "NEX-3N",
+            "NEX-5R",
+            "NEX-5T",
+            "NEX-6",
+            "NEX-VG30E",
+            "NEX-VG900",
+            "DSC-RX100",
+            "DSC-RX1",
+            "DSC-RX1R",
+            "DSC-HX300",
+            "DSC-HX50V",
+            "DSC-TX30",
+            "DSC-WX60",
+            "DSC-WX200",
+            "DSC-WX300",
+        ],
+        4532,
+    ),
+    (&["DSC-RX100M2", "DSC-QX10", "DSC-QX100"], 4204),
+    (
+        &[
+            "DSC-HX60V",
+            "DSC-HX350",
+            "DSC-HX400V",
+            "DSC-QX30",
+            "DSC-RX10",
+            "DSC-RX100M3",
+            "DSC-WX220",
+            "DSC-WX350",
+            "ILCE-7",
+            "ILCE-7R",
+            "ILCE-7S",
+            "ILCE-7M2",
+            "ILCE-5000",
+            "ILCE-5100",
+            "ILCE-6000",
+            "ILCE-QX1",
+            "ILCA-68",
+            "ILCA-77M2",
+            "DSC-HX80",
+            "DSC-HX90V",
+            "DSC-RX0",
+            "DSC-RX1RM2",
+            "DSC-RX10M2",
+            "DSC-RX10M3",
+            "DSC-RX100M4",
+            "DSC-RX100M5",
+            "DSC-WX500",
+            "ILCE-6300",
+            "ILCE-6500",
+            "ILCE-7RM2",
+            "ILCE-7SM2",
+            "ILCA-99M2",
+        ],
+        612,
+    ),
+    (
+        &[
+            "ILCE-6100",
+            "ILCE-6400",
+            "ILCE-6600",
+            "ILCE-7C",
+            "ILCE-7M3",
+            "ILCE-7RM3",
+            "ILCE-7RM4",
+            "ILCE-9",
+            "ILCE-9M2",
+            "DSC-RX0M2",
+            "DSC-RX10M4",
+            "DSC-RX100M6",
+            "DSC-RX100M5A",
+            "DSC-RX100M7",
+            "DSC-HX99",
+        ],
+        594,
+    ),
+];
+
+/// As-shot white balance from the maker note's enciphered `Tag2010` block (bodies that do not write `0x7313` in
+/// the raw IFD: most ARWs before 2017). `model` is the Exif model; Sony appends a regional "V" to some names
+/// (SLT-A77V), which the documented lists omit.
+fn tag2010_wb(model: &str, block: &[u8], order: lightcraft_tiff::ByteOrder) -> Option<[f32; 3]> {
+    let model = model.trim();
+    let &(_, offset) = TAG2010_WB.iter().find(|(models, _)| models.iter().any(|m| model == *m || model.strip_suffix('V') == Some(*m)))?;
+    let bytes: Vec<u8> = block.get(offset..offset + 6)?.iter().map(|&b| DECIPHER[b as usize]).collect();
+    let level = |i: usize| order.read_u16(&bytes, 2 * i).map(f32::from);
+    let (r, g, b) = (level(0)?, level(1)?, level(2)?);
+    // levels are fixed-point gains (green 255–256 on every sample seen); reject implausible values from an unknown layout
+    if !(16.0..=16384.0).contains(&g) {
+        return None;
+    }
+    let (r, b) = (r / g, b / g);
+    ((0.2..=8.0).contains(&r) && (0.2..=8.0).contains(&b)).then_some([r, 1.0, b])
+}
 
 /// The inverse tone curve: 11-bit code → 14-bit sensor value.
 pub(crate) fn code_curve(thresholds: &[u64]) -> Vec<u16> {
@@ -163,6 +300,73 @@ fn read_quad_tiles(bytes: &[u8], info: &ImageInfo) -> Result<Vec<u16>> {
     Ok(out)
 }
 
+/// `SR2Private` tags (ExifTool "Sony SR2Private" table; the IFD is referenced by IFD0's `DNGPrivateData`).
+const SR2_SUBIFD_OFFSET: u16 = 0x7200;
+const SR2_SUBIFD_LENGTH: u16 = 0x7201;
+const SR2_SUBIFD_KEY: u16 = 0x7221;
+/// Black level inside the encrypted `SR2SubIFD` (bodies that do not write `0x7310` in the raw IFD), recovered by
+/// black-box known-plaintext analysis of CC0 raw.pixls.us samples; no description of Sony's cipher was used.
+///
+/// Every Sony ARW we examined (16 files, 15 bodies, 2012–2021) stores the same key (`11 22 33 44`), so its
+/// keystream is the same in every file. The DSC-RX100M6 and ILCE-7M3 also write their black levels in plain form
+/// (`0x7310`: 800 and 512); XOR-ing their `SR2SubIFD`s against each other matched `pack(512×4) ^ pack(800×4)` at
+/// exactly one position, byte 2510, which gave the eight keystream bytes there. Applied to the other files at that
+/// position they decode to four equal levels that agree with each sensor's dark-pixel floor: 800 on every 1″-sensor
+/// body (RX10, RX100 … RX100M5), 512 on the APS-C/full-frame ones (NEX-5N/6, SLT-A77, ILCE-6000/7/7M2/7RM2), in
+/// both `SR2SubIFD` sizes seen (29252 and 56958 bytes). Newer layouts (ILCE-7M4, 35398 bytes) put other data there
+/// and are rejected by the plausibility checks; those bodies write `0x7310` anyway.
+const SR2_BLACK_AT: usize = 2510;
+const SR2_BLACK_KEYSTREAM: [u8; 8] = [0x43, 0xcb, 0x86, 0xb6, 0x11, 0xd2, 0x1a, 0x73];
+const SR2_KEY: [u8; 4] = [0x11, 0x22, 0x33, 0x44];
+
+/// The per-channel black level from the encrypted `SR2SubIFD` (see [`SR2_BLACK_AT`]), in 14-bit units; `None`
+/// unless the file uses the known key and the four decoded levels are equal and plausible.
+fn sr2_black(bytes: &[u8], ifd0: &Ifd, order: lightcraft_tiff::ByteOrder) -> Option<f32> {
+    let private = ifd0.bytes(t::DNG_PRIVATE_DATA)?;
+    let at = order.read_u32(private, 0)? as u64;
+    let opts = lightcraft_tiff::ParseOptions { max_ifds: 1, max_depth: 0, follow_children: false, ..Default::default() };
+    let (sr2, _) = lightcraft_tiff::parse_ifd_at(bytes, at, order, 0, false, &opts).ok()?;
+    if sr2.bytes(SR2_SUBIFD_KEY)? != SR2_KEY {
+        return None;
+    }
+    let (start, len) = (usize::try_from(sr2.u64(SR2_SUBIFD_OFFSET)?).ok()?, usize::try_from(sr2.u64(SR2_SUBIFD_LENGTH)?).ok()?);
+    if len < SR2_BLACK_AT + 8 {
+        return None;
+    }
+    sr2_black_levels(bytes.get(start.checked_add(SR2_BLACK_AT)?..start.checked_add(SR2_BLACK_AT + 8)?)?, order)
+}
+
+/// Decipher the eight `SR2SubIFD` bytes at [`SR2_BLACK_AT`] into one black level (the mean of four near-equal,
+/// plausible per-channel levels).
+fn sr2_black_levels(cipher: &[u8], order: lightcraft_tiff::ByteOrder) -> Option<f32> {
+    let plain: Vec<u8> = cipher.iter().zip(SR2_BLACK_KEYSTREAM).map(|(c, k)| c ^ k).collect();
+    let levels: Vec<u16> = (0..4).filter_map(|i| order.read_u16(&plain, 2 * i)).collect();
+    let (&lo, &hi) = (levels.iter().min()?, levels.iter().max()?);
+    (levels.len() == 4 && (64..=4096).contains(&lo) && hi - lo <= 64).then(|| levels.iter().map(|&v| f32::from(v)).sum::<f32>() / 4.0)
+}
+
+/// The image area for files without Sony's crop tags (`0x74c7/0x74c8`, written since about 2017): the DNG-style
+/// default crop when the raw IFD has one, else the maker note's `FullImageSize` (the camera JPEG's size) anchored
+/// at the top-left. Older bodies store a few columns of padding at the right edge of the raw frame (constant
+/// values, 8–32 columns on the samples we checked) inside a frame 16–48 pixels wider than `FullImageSize`, so
+/// the anchored crop removes them while keeping the CFA phase.
+fn default_crop(raw: &Ifd, mn: Option<&makernote::MakerNote>, w: usize, h: usize) -> Rect {
+    let full = Rect::new(0, 0, w, h);
+    if let (Some([x, y]), Some([cw, ch])) = (raw.u64s(t::DEFAULT_CROP_ORIGIN).as_deref(), raw.u64s(t::DEFAULT_CROP_SIZE).as_deref())
+        && *cw > 0
+        && *ch > 0
+    {
+        return Rect::new(*x as usize, *y as usize, *cw as usize, *ch as usize).clipped(w, h);
+    }
+    match mn.and_then(|m| m.ifd.u64s(MN_FULL_IMAGE_SIZE)).as_deref() {
+        // only a plausible trim: never more than 64 pixels per side, never an enlargement
+        Some([fh, fw]) if *fw as usize <= w && *fh as usize <= h && *fw as usize + 64 >= w && *fh as usize + 64 >= h => {
+            Rect::new(0, 0, *fw as usize, *fh as usize)
+        }
+        _ => full,
+    }
+}
+
 fn raw_ifd(tiff: &Tiff) -> Option<&Ifd> {
     tiff.all_ifds()
         .into_iter()
@@ -215,26 +419,43 @@ pub(crate) fn decode(bytes: &[u8], mode: Mode) -> Result<RawImage> {
         _ => (read_image_in(mode, bytes, &info, tiff.order, Packing::Msb)?, bits),
     };
     let RawData::U16(ref samples) = data else { return Err(RawError::Unsupported("float ARW".into())) };
+    // "12-bit uncompressed" files (e.g. ILCE-7RM2) say BitsPerSample 12 but store 16-bit words on the 14-bit scale
+    // of the other modes (black 512, peaks near 16383): black and white follow the data, `bits` keeps the tag
+    let scale_bits = if info.compression == 1 && out_bits < 14 && strip_len >= (w * h * 2) as u64 && samples.iter().any(|&v| v >> (out_bits + 1) != 0)
+    {
+        14
+    } else {
+        out_bits
+    };
 
     let cfa = match (raw.u64s(t::CFA_REPEAT_PATTERN_DIM).as_deref(), raw.bytes(t::CFA_PATTERN_EP)) {
         (Some([2, 2]), Some(p)) if p.len() == 4 && p.iter().all(|&c| c <= 2) => Cfa { width: 2, height: 2, pattern: p.to_vec() },
         _ => Cfa::bayer_static("RGGB"),
     };
-    let default_black = if out_bits >= 14 { 512.0 } else { 128.0 };
+    let default_black = if scale_bits >= 14 { 512.0 } else { 128.0 };
     let black = match raw.f64s(BLACK_LEVEL).as_deref() {
         Some([a, b, c, d]) => {
             BlackLevel { repeat_rows: 2, repeat_cols: 2, values: vec![*a as f32, *b as f32, *c as f32, *d as f32], ..Default::default() }
         }
-        _ => BlackLevel::uniform(default_black),
+        _ => BlackLevel::uniform(sr2_black(bytes, ifd0, tiff.order).filter(|_| scale_bits >= 14).unwrap_or(default_black)),
     };
-    let white = raw.f64(t::WHITE_LEVEL).map(|v| v as f32).filter(|v| *v > 0.0).unwrap_or_else(|| super::white_from_data(samples, out_bits));
-    let wb = raw.f64s(WB_RGGB).filter(|v| v.len() == 4 && v[1] > 0.0 && v[0] > 0.0 && v[3] > 0.0).map(|v| {
-        let g = (v[1] + v[2]) / 2.0;
-        [(v[0] / g) as f32, 1.0, (v[3] / g) as f32]
-    });
+    let white = raw.f64(t::WHITE_LEVEL).map(|v| v as f32).filter(|v| *v > 0.0).unwrap_or_else(|| super::white_from_data(samples, scale_bits));
+    let model = ifd0.string(t::MODEL).unwrap_or_default();
+    let mn = tiff
+        .exif()
+        .and_then(|e| e.get(t::MAKER_NOTE))
+        .and_then(|e| makernote::parse_makernote(bytes, e.offset, e.count() as u64, tiff.order, &ifd0.string(t::MAKE).unwrap_or_default()));
+    let wb = raw
+        .f64s(WB_RGGB)
+        .filter(|v| v.len() == 4 && v[1] > 0.0 && v[0] > 0.0 && v[3] > 0.0)
+        .map(|v| {
+            let g = (v[1] + v[2]) / 2.0;
+            [(v[0] / g) as f32, 1.0, (v[3] / g) as f32]
+        })
+        .or_else(|| mn.as_ref().and_then(|m| tag2010_wb(&model, m.ifd.bytes(MN_TAG2010)?, m.order)));
     let crop = match (raw.u64s(CROP_TOP_LEFT).as_deref(), raw.u64s(CROP_SIZE).as_deref()) {
         (Some([x, y]), Some([cw, ch])) if *cw > 0 && *ch > 0 => Rect::new(*x as usize, *y as usize, *cw as usize, *ch as usize).clipped(w, h),
-        _ => Rect::new(0, 0, w, h),
+        _ => default_crop(raw, mn.as_ref(), w, h),
     };
     let mut metadata = lightcraft_meta::from_tiff(&tiff);
     metadata.width = Some(crop.width as u32);
@@ -329,6 +550,58 @@ mod tests {
         let _ = code_curve(&[60000, 1, 0, 0]);
     }
 
+    #[test]
+    fn decipher_inverts_the_cube_substitution() {
+        let mut seen = [false; 256];
+        for p in 0..=255u8 {
+            let c = if p < 249 { (p as u32).pow(3) % 249 } else { p as u32 } as u8;
+            assert_eq!(DECIPHER[c as usize], p);
+            seen[DECIPHER[p as usize] as usize] = true;
+        }
+        assert!(seen.iter().all(|&s| s), "not a bijection");
+        assert_eq!((DECIPHER[8], DECIPHER[27], DECIPHER[94]), (2, 3, 7)); // 7³ = 343 ≡ 94
+    }
+
+    fn encipher(plain: &[u8]) -> Vec<u8> {
+        plain.iter().map(|&p| if p < 249 { ((p as u32).pow(3) % 249) as u8 } else { p }).collect()
+    }
+
+    #[test]
+    fn tag2010_white_balance_by_model() {
+        use lightcraft_tiff::ByteOrder::Little;
+        let mut plain = vec![0u8; 700];
+        for (i, v) in [669u16, 256, 441].iter().enumerate() {
+            plain[612 + 2 * i..614 + 2 * i].copy_from_slice(&v.to_le_bytes());
+        }
+        let block = encipher(&plain);
+        let wb = tag2010_wb("DSC-RX100M3", &block, Little).unwrap();
+        assert!((wb[0] - 669.0 / 256.0).abs() < 1e-6 && wb[1] == 1.0 && (wb[2] - 441.0 / 256.0).abs() < 1e-6, "{wb:?}");
+        // same layout (Tag2010h), regional "V" suffix, other layouts, unknown models, truncated or implausible data
+        assert!(tag2010_wb("ILCE-7RM2", &block, Little).is_some());
+        assert!(tag2010_wb("DSC-RX100M3V", &block, Little).is_some());
+        assert!(tag2010_wb("SLT-A77V", &block, Little).is_none()); // Tag2010b: offset 4480 is past the block
+        assert!(tag2010_wb("DSC-RX100M3X", &block, Little).is_none());
+        assert!(tag2010_wb("ILCE-1", &block, Little).is_none());
+        assert!(tag2010_wb("DSC-RX100M3", &block[..615], Little).is_none());
+        assert!(tag2010_wb("DSC-RX100M3", &encipher(&[0u8; 700]), Little).is_none());
+        let mut odd = plain.clone();
+        odd[612..614].copy_from_slice(&9000u16.to_le_bytes()); // R/G ≈ 35
+        assert!(tag2010_wb("DSC-RX100M3", &encipher(&odd), Little).is_none());
+    }
+
+    #[test]
+    fn sr2_black_level_decodes_and_rejects_garbage() {
+        use lightcraft_tiff::ByteOrder::Little;
+        let cipher =
+            |levels: [u16; 4]| -> Vec<u8> { levels.iter().flat_map(|v| v.to_le_bytes()).zip(SR2_BLACK_KEYSTREAM).map(|(p, k)| p ^ k).collect() };
+        assert_eq!(sr2_black_levels(&cipher([800; 4]), Little), Some(800.0));
+        assert_eq!(sr2_black_levels(&cipher([512, 512, 514, 512]), Little), Some(512.5));
+        assert_eq!(sr2_black_levels(&cipher([65320, 64928, 65260, 488]), Little), None); // ILCE-7M4's layout
+        assert_eq!(sr2_black_levels(&cipher([0; 4]), Little), None);
+        assert_eq!(sr2_black_levels(&cipher([800; 4])[..5], Little), None);
+        assert_eq!(sr2_black_levels(&[], Little), None);
+    }
+
     #[test]
     fn quad_tiles_place_cfa_cells() {
         // 14×12 mosaic in 8×8 tiles (the right and bottom tiles overhang), each tile a 4×4 frame of 2×2 cells,

crates/raw/src/vendor/nef.rs

@@ -56,10 +56,17 @@ pub(crate) fn decode(bytes: &[u8]) -> Result<RawImage> {
         if info.compression == t::compression::NIKON { compressed(bytes, &info, mn.as_ref())? } else { uncompressed(bytes, &info, tiff.order)? };
     let RawData::U16(ref samples) = data else { return Err(RawError::Unsupported("float NEF".into())) };
 
+    // Maker note 0x003d is in 14-bit units whatever the sample depth: 12-bit files from the D750, D780, D850,
+    // D7500 and Z 50 store 600 / 1008 / 400 / 400 / 1008 while their darkest samples are 150 / ~252 / 99 / 99 / ~250
+    // (our measurements on CC0 raw.pixls.us samples; the same bodies' 14-bit files match the tag as is).
+    let black_scale = if bits == 12 { 0.25 } else { 1.0 };
     let black = match mn.as_ref().and_then(|m| m.ifd.f64s(BLACK_LEVEL)).as_deref() {
-        Some([a, b, c, d]) if [a, b, c, d].iter().all(|v| **v < 16384.0) => {
-            BlackLevel { repeat_rows: 2, repeat_cols: 2, values: vec![*a as f32, *b as f32, *c as f32, *d as f32], ..Default::default() }
-        }
+        Some([a, b, c, d]) if [a, b, c, d].iter().all(|v| **v < 16384.0) => BlackLevel {
+            repeat_rows: 2,
+            repeat_cols: 2,
+            values: [a, b, c, d].iter().map(|v| (**v * black_scale) as f32).collect(),
+            ..Default::default()
+        },
         _ => BlackLevel::uniform(0.0),
     };
     let wb = mn
@@ -145,6 +152,11 @@ mod tests {
     use lightcraft_tiff::{ByteOrder, IfdBuilder, ImageData, TiffWriter, Value};
 
     fn nef(compression: u16, bits: u16, strips: Vec<Vec<u8>>, w: u32, h: u32, rps: u32) -> Vec<u8> {
+        nef_with_note(compression, bits, strips, w, h, rps, None)
+    }
+
+    /// [`nef`] with an optional maker note (`Nikon\0` v2 header + embedded big-endian TIFF holding `note`).
+    fn nef_with_note(compression: u16, bits: u16, strips: Vec<Vec<u8>>, w: u32, h: u32, rps: u32, note: Option<IfdBuilder>) -> Vec<u8> {
         let mut raw = IfdBuilder::new();
         raw.set(t::NEW_SUBFILE_TYPE, Value::Long(vec![0]));
         raw.set(t::IMAGE_WIDTH, Value::Long(vec![w]));
@@ -158,10 +170,31 @@ mod tests {
         let mut ifd0 = IfdBuilder::new();
         ifd0.set(t::MAKE, Value::Ascii("NIKON CORPORATION".into()));
         ifd0.set(t::MODEL, Value::Ascii("NIKON TEST".into()));
+        if let Some(mn) = note {
+            let mut bytes = b"Nikon\0\x02\x10\0\0".to_vec();
+            bytes.extend(TiffWriter::new(ByteOrder::Big, false).write(&[mn]).unwrap());
+            let mut exif = IfdBuilder::new();
+            exif.set(t::MAKER_NOTE, Value::Undefined(bytes));
+            ifd0.set_child(t::EXIF_IFD, exif);
+        }
         ifd0.add_sub_ifd(raw);
         TiffWriter::new(ByteOrder::Big, false).write(&[ifd0]).unwrap()
     }
 
+    #[test]
+    fn black_level_tag_is_in_14_bit_units() {
+        let (w, h) = (16usize, 4usize);
+        let words: Vec<u8> = (0..w * h).flat_map(|i| (100 + i as u16).to_be_bytes()).collect();
+        let note = || {
+            let mut mn = IfdBuilder::new();
+            mn.set(BLACK_LEVEL, Value::Short(vec![400, 404, 408, 412]));
+            mn
+        };
+        let black = |bits| crate::decode(&nef_with_note(1, bits, vec![words.clone()], w as u32, h as u32, h as u32, Some(note()))).unwrap().black;
+        assert_eq!(black(12).values, vec![100.0, 101.0, 102.0, 103.0]);
+        assert_eq!(black(14).values, vec![400.0, 404.0, 408.0, 412.0]);
+    }
+
     #[test]
     fn uncompressed_word16_and_packed12() {
         let (w, h) = (16usize, 6usize);

crates/raw/tests/corpus.rs

@@ -193,3 +193,99 @@ fn corpus_nef_compressed_matches_uncompressed() {
         assert!(hi <= 4095.0 && hi - lo > 500.0, "D7000 block means {lo}..{hi}");
     }
 }
+
+/// raw.pixls.us has the same D7500 scene as 12- and 14-bit lossless compressed NEF. Both store black level 400 in
+/// maker note 0x003d (14-bit units): after subtracting the black level and scaling to white, the two must agree.
+#[test]
+fn corpus_nef_12_bit_black_level_matches_14_bit() {
+    let dir = corpus_root().join("raw");
+    let (Ok(a), Ok(b)) = (std::fs::read(dir.join("nef-nikon-d7500-lossless12.nef")), std::fs::read(dir.join("nef-nikon-d7500-lossless14.nef")))
+    else {
+        eprintln!("skip: D7500 NEF pair absent");
+        return;
+    };
+    let (a, b) = (decode(&a).unwrap(), decode(&b).unwrap());
+    assert_eq!((a.bits, b.bits), (12, 14));
+    assert!((a.black.values[0] - 100.0).abs() < 1.0 && (b.black.values[0] - 400.0).abs() < 1.0, "{:?} {:?}", a.black, b.black);
+    let normalized = |img: &lightcraft_raw::RawImage| {
+        let (black, white) = (img.black.values[0] as f64, img.white[0] as f64);
+        block_means(img).into_iter().map(|v| (v - black) / (white - black)).collect::<Vec<_>>()
+    };
+    // the two shots aren't pixel-aligned (handheld): compare the distributions, not block by block
+    let (mut na, mut nb) = (normalized(&a), normalized(&b));
+    na.sort_by(f64::total_cmp);
+    nb.sort_by(f64::total_cmp);
+    for q in [0.1, 0.5, 0.9] {
+        let (x, y) = (na[(na.len() as f64 * q) as usize], nb[(nb.len() as f64 * q) as usize]);
+        eprintln!("D7500 12- vs 14-bit: normalized quantile {q}: {x:.4} vs {y:.4}");
+        // with the tag read as 12-bit units, the 12-bit values would sit below black (negative)
+        assert!(x > 0.0 && (0.8..1.25).contains(&(x / y)), "quantile {q}: {x} vs {y}");
+    }
+}
+
+/// Issue #138: DNGs converted by Adobe software carry their camera profile's hue/saturation map and
+/// look table; we read them (and render with them). Camera-written DNGs here carry none.
+#[test]
+fn corpus_adobe_dngs_carry_profile_looks() {
+    let dir = corpus_root().join("raw");
+    let Ok(rd) = std::fs::read_dir(&dir) else {
+        eprintln!("skip: {} absent", dir.display());
+        return;
+    };
+    let mut seen = 0;
+    for p in rd.flatten().map(|e| e.path()) {
+        let name = p.file_name().unwrap().to_string_lossy().to_lowercase();
+        if !name.starts_with("dng-") || !name.ends_with(".dng") {
+            continue;
+        }
+        let info = probe_info(&std::fs::read(&p).unwrap()).unwrap_or_else(|e| panic!("{name}: {e}"));
+        let look = &info.color.profile;
+        if name.starts_with("dng-adobe-") {
+            seen += 1;
+            let hsm = look.hue_sat_map[0].as_ref().unwrap_or_else(|| panic!("{name}: no hue/sat map"));
+            assert!(hsm.hue_divisions > 1 && hsm.sat_divisions > 1, "{name}");
+            assert!(look.look_table.is_some(), "{name}: no look table");
+            // a profile applied to a mid grey keeps it (close to) neutral
+            let t = lightcraft_raw::profile::ProfileTables::new(look, 0.5).unwrap();
+            let g = t.apply([0.18; 3], 1.0);
+            assert!(g.iter().all(|v| (v - g[0]).abs() < 0.01 * g[0].max(0.01)), "{name}: grey → {g:?}");
+        }
+        eprintln!(
+            "{name:44} profile look: hsm {} look {} tone {}",
+            look.hue_sat_map[0].is_some(),
+            look.look_table.is_some(),
+            look.tone_curve.is_some()
+        );
+    }
+    eprintln!("{seen} Adobe-converted DNGs checked");
+}
+
+/// Issue #148: Sony ARWs from before ~2017 carry no plain white-balance, black-level or crop tags in the raw IFD.
+/// White balance comes from the maker note's enciphered `Tag2010`, the black level from the encrypted `SR2SubIFD`
+/// and the crop from `FullImageSize`; without them the RX100 III opened bright green. Expected values: the black
+/// levels agree with each sensor's dark-pixel floor, the gains with the neutral sky of the camera JPEG.
+#[test]
+fn corpus_sony_pre2017_colour_metadata() {
+    let dir = corpus_root().join("raw");
+    // (file, black, approximate R and B gains, crop width × height)
+    let cases = [
+        ("arw-sony-rx100m3.arw", 800.0, [2.61, 1.72], (5472, 3648)),
+        ("arw-sony-rx100.arw", 800.0, [2.23, 2.00], (5472, 3648)),
+        ("arw-sony-a7rm2-12bit-uncompressed.arw", 512.0, [2.58, 1.46], (7952, 5304)),
+    ];
+    let mut seen = 0;
+    for (name, black, [r, b], (cw, ch)) in cases {
+        let Ok(bytes) = std::fs::read(dir.join(name)) else {
+            eprintln!("skip: {name} absent");
+            continue;
+        };
+        let img = decode(&bytes).unwrap_or_else(|e| panic!("{name}: {e}"));
+        assert_eq!(img.black.mean(), black, "{name}: black level");
+        let wb = img.wb_multipliers.unwrap_or_else(|| panic!("{name}: no as-shot white balance"));
+        assert!((wb[0] - r).abs() < 0.01 && wb[1] == 1.0 && (wb[2] - b).abs() < 0.01, "{name}: white balance {wb:?}");
+        assert_eq!((img.crop.width, img.crop.height), (cw, ch), "{name}: crop");
+        assert!(img.white_at(0) > 16000.0, "{name}: white {} (14-bit scale)", img.white_at(0));
+        seen += 1;
+    }
+    eprintln!("pre-2017 Sony ARW colour metadata checked on {seen} files");
+}