Disclaimer: I am not a color buff. Anybody who actually *knows* about 
that stuff, please chime in.

While writing the Lab/LCH layer mode stuff, I wondered so far why the 
result is still slightly different from the current GEGL implementation 
of Color/Hue/Saturation/Value modes.

Now after taking a quick peek at the babl source, it seems that 
GEGL/babl assumes a PAL/SECAM RGB space as source (just like the 
Decompose plug-in.)

Considering that two different implementations use PAL/SECAM, I am 
wondering if there is a good reason for it and I just don't understand; 
or if maybe they just either copied from each other or happened to 
reference the same (limited) resource?
After all, accurate color conversion information isn't abundant and was 
probably less so when that code was written.

So far I'd say it's a bug -- barring actual color management the most 
reasonable assumption seems to be sRGB.

D50 vs D65
Another question during transformation to Lab is, which illuminant or 
reference white to use.

That part, I don't quite understand yet. Does that depend on the source 
data, or simply on how the monitor is calibrated?

I'll be grateful for any enlightenment.


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