ImageBitmap resize quality test

Compare how this browser reduces a 2048×1536 PNG to 256×192. The canonical stress chart is identified when selected, but other images work too.

Choose source PNG

Original source

Selected 2048×1536 source. The overview is scaled only by CSS.

640×512 source crop at 1:1 pixels

Browser outputs

Each native output is followed by a 3× zoom using nearest-neighbor scaling. MAE is the mean absolute per-channel RGB difference from the exact 8×8 area average; max is the largest single-channel difference; >12 is the percentage of pixels whose mean RGB difference exceeds 12. Alias RMSE is measured against the reference in the five above-Nyquist checker bands. Edge is the FWHM of the diagonal red stripe's chroma profile in destination pixels (lower is sharper); ring is its largest chroma overshoot or undershoot. Difference maps amplify each absolute RGB channel error 8×. The reference is diagnostic, not a required rendering algorithm.