A small, self-contained Python script that inspects a single frame (or folder of frames) for color artifacts WITHOUT a reference, using three blind checks on the color channels: (1) chroma detail ratio — the L2 (squared-gradient) edge energy of the color channels relative to the brightness channel, which drops when subsampling softens color edges (mean/L1 gradient is conserved by subsampling and cannot see it, which is why the script uses squared-gradient energy); (2) chroma edge width in pixels
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The handbook · 7 volumes
Fora Soft Video Engineering Handbook
This no-reference color-artifact detector checks a frame for color artifacts using chroma detail ratio, chroma edge width and other blind checks on the color channels. Our seven-volume handbook covers the full video stack; start with Volume 1 for color spaces, chroma subsampling and quality metrics, then Volume 3 for delivery and Volume 6 for AI quality models. Written by Nikolay Sapunov, CEO at Fora Soft.
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