Color Blending Post Encoding?

[Sharc]

Ermm, out4 doesn't seems to work for me (I used the exact same script but with the full loseless file and not just a part). Is your Histogram also identical? Because as you can see on the picture above, it's a bit different (which made sense to me because Jagbo said moving Level/Tweak is not accurate).

Yes, the histograms are identical. In tweak you have to set bright=-62.5 though as -41*256/168=-62.47.
What do you mean by 'out4 doesn't seem to work'? What do you get?
I doubt that tweak will keep more details than Levels()+MergeChroma, but one has to make an extra 'manual' step for calculating the corresponding tweak values. But of course it's totally up to you which method you prefer

[Okiba]

No error. Just Grey screen. But it's probably because I/Jagbo used 62 and the finer value is 62.47. Could be what modified the Histogram. Will check

[Sharc]

No error. Just Grey screen.

Well, a grey screen is exactly what one expects for out4 when the 2 variants A and B produce identical results, means when the difference is zero

[Okiba]

Oh, I see. Should have checked what Subtract do

[Sharc]

Look at the RGB cube inside the rec.601 YUV (YCbCr) cube:


[Attachment 55405 - Click to enlarge]
(That image originally came from https://software.intel.com/en-us/node/503873. But Intel appears to have (re)moved it.)

It's available from here now:
https://software.intel.com/content/www/us/en/develop/documentation/ipp-dev-reference/t...ml?language=en

... and similar from here:
https://scc.ustc.edu.cn/zlsc/sugon/intel/ipp/ipp_manual/IPPI/ippi_ch6/ch6_color_models.htm

[jagabo]

Sharc, thanks for those links. I've updated my shortcuts.