From: James Courtier-D. <Ja...@su...> - 2003-11-02 16:26:06
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Michael Roitzsch wrote: > Hi Billy, > > >>>What's the difference? >> >> When specifying the colourspace it is good to say Y'CbCr since it >>makes it more clear that Y' is different from the Y in the XYZ >>colourspace, since luma, Y', is calculated from gamma corrected RGB >>and luminance, Y, is calculated from linear intensity RGB. >> >> http://www.poynton.com/PDFs/YUV_and_luminance_harmful.pdf > > > Wow, I would have never thought of the possible confusion with CIE's Y > component. This guy is damn right. Y' it is then. > > >> To distinguish gamma corrected RGB from linear intensity RGB, >>Poynton uses the notation R'G'B' for gamma corrected, RGB for linear >>intensity. I think this covers it: >> >> http://www.inforamp.net/%7Epoynton/PDFs/TIDV/Gamma.pdf > > > Ok, another matter of notation. But in analogy to above, R'G'B' sounds > more logical to me. In my statements, I always meant the non-linear > versions, of course. > > Thanks a lot for the useful pointers. > > Michael > I think Poynton's terms are the de-facto standard, so I think we should update the xine-lib source to use the correct terms. |