mirror of
https://github.com/storytold/photocraft.git
synced 2026-11-02 22:30:20 -06:00
becc27ac1c
* Lab and CMYK: Invert, Posterize and Threshold work on the document's channels Photoshop applies these to each stored channel, not to RGB: - Lab: Invert and Posterize work on L, a and b, and Threshold cuts on L to a neutral black or white. - CMYK: Invert and Posterize work on each ink, black included, so paper inverts to 400% ink. Threshold gives paper or 100% black ink. Adjustment layers now do the same: - compose::adjust::apply_mode goes through the document's Lab or CMYK channels. - The GPU falls back to the CPU for these, as it already does for Lab/CMYK Levels and Curves. - The destructive Image > Adjustments path works on the stored samples directly, so it is exact. Photoshop oracles (lab/cmyk 8 and 16 bit), bad pixels before -> after: - lab threshold: PASS (was 12%) - lab invert: 72-99% -> 1% - lab posterize: 89% -> 0.1% - cmyk invert: 77% -> 10% - cmyk posterize: 71% -> 9% - cmyk threshold: 37% -> 1.6% Floor 133 -> 139 (137 already passed on main). Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> * CMYK: Invert, Posterize and Threshold on the inks; 16-bit Lab Invert keeps greys neutral Builds on main's adjust::apply_in (#4038): - apply_in's mode dispatch gains CMYK. Invert and Posterize work on each ink, black included, so paper inverts to 400% ink. Threshold gives paper or 100% black ink alone. cmyk_channel_adjustment says which adjustments do this. - Lab Invert mirrors a and b around neutral at 16 bits; 8-bit bytes still become 255 - v. stored_channels holds both rules, and apply_lab uses it. - Destructive Image > Adjustments on a Lab or CMYK layer works on its stored channels directly, so it is exact; a selection mixes the stored values. - The GPU leaves CMYK Invert, Posterize and Threshold to the CPU. Photoshop oracles, bad pixels: - cmyk invert: 77% -> 10% - cmyk posterize: 71% -> 9% - cmyk threshold: 37% -> 1.6% - lab16 invert: 52% -> 1.2% The count stays at 145/258, which main already passes, so the floor goes 133 -> 145. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> --------- Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com> Co-authored-by: Brandon Thomas <echelon@gmail.com>