Add registered RGB comparison after area reduction and low-pass filtering, retain the texture exception, and cover metadata stripping plus resize/blur/translation with synthetic fixtures. Verified against the five replaced room plates in the Gemini hotel replay. Implemented and tested with AI assistance.
Source-pixel regression fixtures
reference.png is synthetic RGB artwork with smoothly varying color, shapes,
and fine noise. independent.png uses the same palette and construction with a
different seed. Neither contains photographs or user artifacts.
transformed.png reproduces the image-processing sequence observed in a Gemini
comp-led eval. From this directory:
magick reference.png -strip -resize 300% -scale 94% -scale 106.38% -blur 0x0.7 -roll +2+1 transformed.png
The crate test verifies the PNG has no retained source metadata. The gate test adds an invented generation prompt before checking it: prompt metadata is not proof of generation. Texture patches retain their explicit exemption.
This is a regression for resampling, mild blur and small translations, not a claim to identify every possible transformed copy. The independent-pixel and flat-field checks guard against treating a shared palette as proof of copying.
detailed-reference.png is a synthetic grid of colored panels with hard edges
(seed 917). detailed-transformed.png applies the same command to it, guarding
against aliasing during differently sized image comparisons.