[Openicc] meta data in test chart

[Graeme Gill]

Chris Murphy wrote:

> Use of the PRMG would be useful here, in theory, because the idea is that the image is
> rendered scene-referred to output-referred once in something like ProPhoto RGB. The
> problem is that Adobe RGB and ProPhoto RGB do not come in v4 versions that make use of
> the PRMG. And then also there are no widely available v4 + PRMG output device profiles.
> So as far as I'm concerned ICC v4 and the PRMG are in a coma for mainstream users.

Hmm. I'm don't think that the PRMG helps in any way. You still need to identify
the source gamut. If your source profile is ProPhoto, what gamut is mapped
to the PRMG in the A2B table ? If you map the ProPhoto gamut, most images
encoded in that space will end up looking very dull when linked with
(say) a printer profile that then maps from the PRMG to the printer gamut.

Graeme Gill.