- finish: sRGB encode through an interpolated 4096-entry table (< 2e-5 from the exact curve,
tested), exp2 instead of powf(2, x).
- guided / guided_fast: coefficient and output passes run row-parallel (were serial loops);
Image::zip_map.
- blur_bench reports process CPU time next to wall-clock (meaningful on a loaded machine).
- RENDER_CACHE_VERSION 3 (exposure-after-filters and the table change pixels by <= 2 LSB).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
