scott wrote:
>> Those mystery numbers are actually the values that determine the make 
>> up of the resulting channels so, in the example of XYZ -> RGB R is 
>> actually made up of 0.412453 X, 0.357580 Y, 0.180423 Z ... its 
>> actually really simple!
> 
> Yep, that's all matrix multiplication is, just a compact way of writing 
> out those 3 equations of 3 variables :-)
> 
> BTW, the mappings that you can do by a matrix only convert to/from 
> *linear* RGB.  When you show them on a display you need to gamma correct 
> them (or if you get a bitmap from somewhere, you need to undo the gamma 
> first before conversion).

And components in some schemes can't be derived as a linear combination 
of values from another scheme.  Hue, for instance.  A line parallel to 
the H axis in an HSV color scheme does not map to a straight line in RGB.

Regards,
John

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