The decoder reads a codestream incrementally, checks its dimensions before loading the remainder, and applies a caller-selected compressed-input, pixel-count, and tracked-decoder-allocation budget. jxl-oxide's allocation tracker cannot account for every allocation made by the decoder, and the input slice is already owned by the caller. The decoder returns the first frame as interleaved f32 samples together with source and rendered color metadata. It does not perform an external ICC transform; callers that need color-managed output should use the returned profiles with their CMS. CMYK output is rejected because this crate does not bundle an external CMS.

decode_with_color can request linear Rec. 2020 for enum-encoded images. XYB is rendered through linear sRGB and converted to Rec. 2020 to avoid the known wide-gamut XYB rendering issue in jxl-oxide. If a source embeds an ICC profile, the decoder keeps the source-profile samples and returns the profile; it does not claim to transform ICC data without a CMS. decode retains the decoder's default rendering target.

The encoder accepts interleaved 8-bit, 16-bit, or HDR floating-point samples. Floating-point input is linear-light and is currently available only with the Rec. 2020 PQ option; one input unit maps to 203 cd/m². Gray input is expanded to RGB, and opaque alpha is omitted. ICC data is embedded in lossless output; Exif and XMP boxes are written when provided. Encoding is unavailable on wasm32 targets.

jxl-oxide is MIT OR Apache-2.0. jixel is BSD-3-Clause OR Apache-2.0.