Help required: Getting primary illuminants and white point from ICC file

[Graeme Gill]

Richard Hughes wrote:

> I've just added code to git master to do this, and it indeed works to
> get the gamut range for a few scanner and print (RGB) profiles I've
> got here. It doesn't seem to work for CYMK profiles, although I'm sure
> that's something crazy I'm doing (or not doing..).

Subtractive media profiles usually have less easily defined gamut
extents than additive (RGB) profiles. Unlike additive, you can't
expect it to be a nice polygon in XYZ/xy/u'v' space. Something
roughly accurate for a chromaticity diagram would involve sampling
along the color girdle (ie. going through combinations between CMY: 1 0 0,
1 1 0, 0 1 0, 0 1 1, 0 0 1, 1 0 1,
e.g. 1 0 0, 1 .1 0, 1 .2 0 .. 1 .9 0, 1 1 0, .9 1 0, .8 1 0, ... etc.)

Graeme Gill.