>> - XYZ colorspace does not represent all colors... just all the colors
> that
>> people can see.
>
> It's the CIE Lab colorspace that represents the gamut of (normal) human
> vision.
>
I misinterpretted his original comment and thought he was talking
about CIE XYZ colorspace, not an "XY" colorspace with "XY" being a
placeholder.
XYZ is an absolute colorspace that attempts to model the way that
trichomatic human vision functions (rods, cones, etc). Lab is another
colorspace based lossless mathematical transformation of XYZ. It has the
tangible benefit of providing "lightness" (i.e. B&W) channel in addition
to two color channels so it's more intuitive for people to think about.
It also has the benefit of having a gamut that models all of the visible
spectrum.
Again, using a wider colorspace during processing *can* have
benefits to the final product... even if it's printed on paper. It's not
too likely, but it is possible. Basically the same argument as why 16-bit
color is better for processing when only 8-bits are printable/perceptible
in the final output.
It should also be reiterated that if done *improperly*, using a
wider colorspace will *REDUCE* the quality of the final product due to
posterization or just downright errors in color profiling and conversion.
> Trivia: Approximately 1% of women have tetrachromatic color vision -
> that is, four different types of cone cells in their retinas - and can
> see a vastly broader gamut than normal people. Exactly 0% of men have
> this ability; you need two X chromasomes to get it.
>
Interesting.
-Cory
--
*************************************************************************
* Cory Papenfuss, Ph.D., PPSEL-IA *
* Electrical Engineering *
* Virginia Polytechnic Institute and State University *
*************************************************************************
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