Original PickImageColors density-only PNG experiment, October 11, 2026. Two 240x120 opaque RGB images, same pixel/IDAT data, different pHYs density. Run check-density.py with Python and Pillow. Six actual public-tool clicks are recorded separately. Requested DPI labels are not exact stored values: the PNG stores integer pixels per metre. This test is limited to these two files and one Chrome session.
