[Openicc] review of new wide gamut editing space

[Chris Lilley]

On Wednesday, March 21, 2012, 5:42:02 PM, Kai-Uwe wrote:

KUB> Hello all,

KUB> some software projects want to preserve wide gamut data like originating
KUB> from cameraRAW. ProPhotoRGB, which's gamut appears quite reasonable,
KUB> specifies unfortunately a gamma of 1.8, which is not good for 2.2/sRGB
KUB> style display systems. 

A couple of months ago I was in a meeting with some colour experts at Canon. I bad-mouthed ProPhoto a bit (over wide gamut, gamma of 1.8).

It later turned out I was talking to one of the authors of ProPhoto. He subsequently offered to send me some design rationale documentation.

KUB> Ideally we find a colour space to use as a intermediate
KUB> space for displaying and storage for inclusion into the OpenICC profile
KUB> collection.

I have been using BetaRGB by Bruce Lindbloom, which is a suitably wide - but not too wide - gamut, 2.2 gamma and D50 wp. the design rationale is here:
http://www.brucelindbloom.com/index.html?BetaRGB.html


KUB> I created a editing profile with gamma of CIE*L following the 
KUB> ECIv2/LStar-RGB profile and used the wide gamut colour primaries of 
KUB> ProPhotoRGB alias ROMM [1].

Isn't an L* transfer curve even worse for a 2.2/sRGB style system?

The monitor reviews on prad.de seem to have the worst results when trying to profile to eciRGB_v2 which uses L*




-- 
 Chris Lilley   Technical Director, Interaction Domain                 
 W3C Graphics Activity Lead, Fonts Activity Lead
 Co-Chair, W3C Hypertext CG
 Member, CSS, WebFonts, SVG Working Groups