[Openicc] Open Source compatible AdobeRGB profile

[Gerhard Fuernkranz]

Graeme Gill wrote:
> Given the issues with ICC V4 display profiles not supporting Absolute
> Colorimetric Intent, I'm not sure a V4 profile is all that desirable.

Graeme, why "not supporting absolute colorimetric intent"? I understand 
that a correct V4 profile does contain all information needed by a CMM 
to compute both kinds of absolute intent, a "true" absolute reproduction 
(CIE absolute colorimetry), and also the (illuminant relative) 
ICC-absolute reproduction as defined in the ICC V4 spec. It's up to the 
user of the profile to do the desired thing with the information 
recorded in the profile.

The question is probably rather, can all CMMs handle V4 profiles 
properly yet? And of course, as the Adobe RGB 1998 profile is obviously 
a V2 profile, the compatible one should probably be a V2 profile too, 
for best interoperability with V2-only CMMs, shouldn't it?

IMO the problematic ones are rather those V2 display profiles, which 
generally record D50 in the 'wtpt' tag (i.e. the true WP adapted to D50, 
which gives always D50) and which furthermore do not contain a 'chad' 
tag. The information recorded in these profiles is indeed insufficient 
to reconstruct the true white point chromaticity and to compute "true" 
absolute colorimetry.

(But Adobe RGB 1998 does not belong to the latter class anyway, but 
records D65 in the 'wtpt' tag, as also does the old sRGB profile from 1998)

Regards,
Gerhard