Original PickImageColors two-frame test. PNG controls are included, so no conversion is required to repeat the online sampling. Optionally run python extract_frames.py with Pillow installed to decode the GIF into extracted-00.png and extracted-01.png. Frame numbering starts at zero. Both full-frame opaque source images are 300x100; each lasts 1000 ms. UI readings are separate from Pillow file verification. Sample centers x=50,150,250 and y=50. This limited experiment does not test all GIF encodings or browsers.
