MrCloudy2andClaude Opus 5.5 04d2874e38 fix(image): 32 Bits/Channel holds linear light, as in Photoshop (#3792) ...

PhotoCraft treats 32-bit documents as linear light (Transfer::for_document,
Exposure, Photo Filter, PSD import), but Image > Mode > 32 Bits/Channel only
rescaled the samples, so a converted 8-bit grey 128 stayed 0.502. Photoshop
stores 0.2159 (measured in Photoshop 27.11: 32-bit float TIFF of an sRGB
chart, every sample = the sRGB-to-linear value). The conversion now decodes
colour samples through the document's tone curve after widening to 32 bits,
and encodes them before narrowing (so no linear value is quantised to 8 or
16 bits). Alpha, masks and alpha channels keep their values. RGB and
Grayscale only (the 32-bit modes).

With it, Photoshop's 32-bit results match exactly for the conversion itself,
Levels, Black & White (default), Brightness/Contrast and Colorize (were 40-80
levels off in sRGB terms).

Adds Surface::map_color (colour samples only, including the default pixel)
and makes Transfer::decode/encode public.

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>

2026-10-12 08:45:48 -04:00

..

src

fix(image): 32 Bits/Channel holds linear light, as in Photoshop (#3792)

2026-10-12 08:45:48 -04:00

Cargo.toml

one-shot

2026-09-30 05:02:08 -04:00