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kronbiiandClaude Opus 5.5
ff227b770c
Scanned pages looked thin and broken at screen size. An image that does not ask for /Interpolate (most scans) was pre-shrunk with nearest-neighbour since about one sample in ten and dropped most strokes of its text, and the nearest sampler then read the shrunk raster again at a fractional offset. - Shrinking (vendored hayro patch 21): non-interpolated images outside Type 3 glyphs are area-averaged (area_shrink: each device pixel the coverage-weighted mean of the samples it covers, 16.16 fixed point whose weights sum to exactly one, premultiplied when masked) to their snapped device rectangle and drawn 1:1. /Interpolate governs smoothing when an image is enlarged (ISO 32000-2 8.9.5.3); averaging adds nothing between samples and drops none. PicScale's Box/Area filters were not usable: shrinking, they average a window four target pixels wide. - Enlarging (patch 28): an image of page-scan size (512+ samples on its shorter side) is drawn bilinearly when enlarged, so a zoomed scan has no staircase edges; icons, QR codes and pixel art keep their hard pixels. - A snapped image whose shrink failed keeps the full transform instead of being drawn at its source size (latent in the interpolated path too). Measured on a 13-page 300 dpi scan at 96, 120 and 192 dpi: every rendered sample is within 1 of the exact area average (it was up to 255 off, 17-23% of samples by more than 1). Bilinear zoom costs nothing measurable (four 1024 px tiles at 400%: 50 ms, nearest 48 ms; bicubic was 267 ms). Review fixes: - a tile snaps a shrunk image's half-pixel edges where the whole page does - a scan shrunk one way is smoothed the way it is stretched - a smaller soft mask doesn't let transparent colour through the area shrink Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>