[Openicc] shared-color-profiles issues [was: new/old ICC profile package]

[Graeme Gill]

glennrp at comcast.net wrote:
> How did the sRGB profile become public domain?

I released an sRGB profile under the public domain.

> The iCC seems to think it's copyright and licensed
> by them with a BSD-like license.

The ICC offers it's own sRGB profiles that are not
compatible with the original, very widely distributed
HP/Microsoft sRGB profile. The profile I've provided
is interchangeable with the original HP/Microsoft profile.

> I wasn't aware that ICC has approved 5 different sRGB
> profiles (actually 3 different with 2 deprecated names).

It's not up to the ICC to approve sRGB profiles. The sRGB
spec. is publicly available, so anyone can create an ICC profile
that represents the sRGB device space.

> I wonder which one we mean by the PNG sRGB chunk?  I
> guess the v2 without black-point.

In my book it's the original HP/Microsoft profile, since
the ICC V2 sRGB profiles have incompatible absolute colorimetric
behaviour, and are therefore unsuitable for soft proofing.
I also regard one of the two V2 sRGB profiles on the ICC
website as not being ICC V2 compliant, since it claims perceptual
intent for a matrix profile, and causes problems with lost shadow
detail. I also think that it's poor practice from the ICC to be
distributing these incompatible V2 sRGB profiles, creating confusion
and problems for users.

Graeme Gill.