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Old 22nd August 2019, 23:37   #187  |  Link
Warner306
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Join Date: Dec 2014
Posts: 1,127
Quote:
Originally Posted by j82k View Post
Found another really strange behavior of the C8 using the HDR color clipping test pattern from here:
https://drive.google.com/drive/folde...DUewbFsSXY1r8p

There is a big difference of clipping points with certain colors depending on the color format output.
It's especially noticeable with red and green. I used passthrough HDR and levels were of course set correctly.


Red:
RGB full/limited - clips at ~590
YCbCr 444/422 - clips at ~820

Green:
RGB full/limited - clips at ~780
YCbCr 444/422 - clips at ~590

With other colors the difference wasn't that big but what's really strange is that red clips much earlier with RGB output but with green it's the opposite, it clips much earlier with YCbCr. These big differences can't be minor color conversion rounding errors right? Anyone able to confirm or explain this??
YCbCr and RGB are different color spaces of different sizes. I don't think that explains a large difference in color clipping, though. YCbCr converted to RGB is slightly larger than PC RGB converted to display RGB.

RGB untouched by madVR and presented in PC mode should be the most accurate rendition without having to account for any errors by the GPU conversion to YCbCr or the display using the wrong color matrix for RGB to YCbCr 4:2:2 to RGB.

Last edited by Warner306; 22nd August 2019 at 23:41.
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