Re: gcm and firefox color management

[Richard Hughes <hughsient gmail com>]

On 13 September 2011 19:13, ivvmm <me detected gmail com> wrote:
> I've recently bought a x-rite huey colorimeter, installed GCM 2.30.2,
> profiled my LCD, enabled full color management in firefox.

Cool.

> The question is, in firefox, when I view black and white images with no
> ICC profile embeded I see a slight green shade in dark areas. Is this
> normal? I can even distinguish that by measuring color with the
> GIMP(make a screenshot of browser session, then measure RGB components).

Right, it depends on whether the profile you created was a v2 or v4
profile. I can't remember which was the default in 2-30. Firefox has a
pretty crappy color library called QCMS[1] which only supports v2
profiles (although, iirc, you can set gfx.color_management.enablev4 to
1 on some builds)

> In about:config of firefox gfx.color_management.mode is set to '1'(it is
> full color management). If I set gfx.color_management.mode to '2'(color
> manage only images with embeded ICC profile) black and white images with
> no ICC profile embeded show up normal, they do not have green shade.

I'm not sure how precisely firefox is working internally. I assume "1"
means everything without a color profile is assumed to be sRGB" and
"2" means "only correct images where I know the source profile".

Maybe someone more familiar with the firefox CMS might be able to shed
some light on the 'green' issue?

Richard.

[1] https://bugzilla.mozilla.org/show_bug.cgi?id=488800