Doom9's Forum - View Single Post - Manual White Balance in YUV without converting to RGB

Gavino · 3rd March 2014, 12:26

Regarding ColorYUV(autogain=true), it simply adjusts the gain_y and off_y parameters, on a per-frame basis, to put the darkest pixel in each frame at y=16 and the brightest at y=236 (not 235, for some reason!).
The levels parameter ("TV->PC" or "PC->TV") is ignored in this process.

EDIT: It's a little more complicated if you have existing pixels outside the range [16,236]. What actually happens is it sets gain_y and off_y so that the range [max(yMin, 16), min(yMax, 236)] is mapped to [16,236].

3rd March 2014, 12:26	#3 \| Link
Gavino Avisynth language lover Join Date: Dec 2007 Location: Spain Posts: 3,431	Regarding ColorYUV(autogain=true), it simply adjusts the gain_y and off_y parameters, on a per-frame basis, to put the darkest pixel in each frame at y=16 and the brightest at y=236 (not 235, for some reason!). The levels parameter ("TV->PC" or "PC->TV") is ignored in this process. EDIT: It's a little more complicated if you have existing pixels outside the range [16,236]. What actually happens is it sets gain_y and off_y so that the range [max(yMin, 16), min(yMax, 236)] is mapped to [16,236]. __________________ GScript and GRunT - complex Avisynth scripting made easier Last edited by Gavino; 3rd March 2014 at 12:45.