Re: gcm with Gimp, EOG, Darktable & Co

[Øyvind Kolås <pippin gimp org>]

On Wed, Apr 18, 2012 at 11:56 PM, Pascal de Bruijn <pmjdebruijn pcode nl> wrote:
> He's probably confusing VideoLUT with the xyz matrix. They are
> supposed to be used together and complement each other.

Assuming that we have an ICC profile for how a monitor renders the
colors given to it as input. If colord/gcm is doing any adjustment to
the display - yet another (different) profile would be needed for GIMP
to transform its colors based on this approximation; or you could
assume that the approximation is good enough.

It might be that colord/gcm is telling GIMP about a different system
profile than the ICC profile actually used - then ticking "use system
profile" should work correctly.

Using the same ICC profile in both colord/gcm and GIMP does as far as
I can tell lead to double color correction.

The comment about better off with color management disabled is about
GIMP likely doing 4,16,64,256x too many pixel conversions with lcms
for when zooming out of large images. at respectively 50, 25, 12.5 and
6.25% zoom levels.

/Øyvind K.
--
«The future is already here. It's just not very evenly distributed»
                                                 -- William Gibson
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