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Old 16th August 2019, 22:06   #85  |  Link
jpsdr
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Join Date: Oct 2002
Location: France
Posts: 2,309
pColor and also pRx,pRy,pGx,pGy,pBx,pBy,pWx,pWy are used only to compute the Min/Max values of XYZ, which are not a stable [0,1] in all situations like RGB, but are White Point and R,G,B point chromaticity dependent.

With this, with integer format, 16 bit for exemple, i can affect [0]=Min(X,Y,Z) [65535]=Max(X,Y,Z) in the inputs. These previous parameters have no effect in float format. The parameter is here for optimal theorical performance, but i don't know if it will produce real visible effect between the standard BT. It will if you use different White Point (his has the biggest effect), or realy very different R,G,B point.

Roughly, range is Y [0,1.00], X[0,0.96], Z[0,1.10]. Didn't check more decimal, but maybe for BT.709 max Z is 1.1001 and for BT.2020, max Z is 1.002. I think it's something like that, realy no more.
Well, the previous parameters are here to be sure you have input proper range value used in integer mode.

And again, of course, no effect in float mode because no needs.

Described also in the Warning page 3 of ColorConversion.pdf document i've provided within the binaries package.
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Last edited by jpsdr; 16th August 2019 at 22:28.
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