[argyllcms] Re: Fluorescence

> they aren't illuminant independent, but they contain enough information,
> in order that *both*, a) the "true" absolute XYZ colors (under the
> actual viewing illuminant)

Actual viewing illuminant? You mean "adapted" from their D50-based original
values? 

> and b) an illuminant relative transformation
> from the viewing illuminant to D50 (that's how ICC-absolute intent is
> actually interpreted by the ICC!)

Viewing illuminant? That's starting to sound chinese to me :((

> can be computed from the profile.

OK.

> Without 'chad' tag, this is not possible,

Right. It's not possible to adapt the colorimetry out to anything else
without this information, as far as I know.

> except in the special case,
> that the profile is made for a D50 viewing illuminant (in the latter
> case (a) and (b) will give the same results).

Then, all D50-based measurements of my spectro in reflectance mode are
considered "made for a D50 viewing illuminant", right?

This is so confusing. Why did they change the rules?

Roger Breton  |  Laval, Canada  |  graxx@xxxxxxxxxxxx
http://pages.infinit.net/graxx

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