DCP-o-matic

Hi

By mistake, I created some patterns in Adobe Wide Gamut RGB <https://en.wikipedia.org/wiki/Wide-gamu ... olor_space>. I can transform them, or start over, but I thought I would try DOM’s capability first.

From that site, I get the following values to use (the white point being D50). I’d like to verify how to use the “Input gamma correction”. The wikipedia link says that “...a gamma of 2.2 is assumed, without the linear segment near zero that is present in sRGB. The precise gamma value is 563/256, or 2.19921875.” Perhaps using the "Simple gamma" pull-down and using that number? Perhaps the difference between that and 2.2 is insignificant?

Anyone with experience with this?

Many thanks.

C J Flynn
Cinema Test Tools https://www.cinemates ... gers-walk/

I thought sRGB always uses a 'simple' (single) gamma, and only rec709 has the initial linear segment?

- Carsten

I have so little experience with sRGB and 709 at this level...but I have even less with Wide Gamut RGB which its huge color space. And, there is so little data on it...just an off-handed paragraph here or there. Unfortunately I don't have the cinema available that I used to have for testing or I could experiment away a few hours.

Carsten wrote: ↑Tue Oct 31, 2017 7:16 pm I thought sRGB always uses a 'simple' (single) gamma, and only rec709 has the initial linear segment?

- Carsten

Forget it, the above statement is wrong. For Adobe Wide Gamut:

'Similar to Adobe RGB, a gamma of 2.2 is assumed, without the linear segment near zero that is present in sRGB. The precise gamma value is 563/256, or 2.19921875.'

For me it looks as if the simple Gamma 2.2 and the primary coefficients from the wikipedia article should deliver a suitable conversion.



- Carsten