[Openicc] seeking for advice on rendering intent and black point compensation

[Sven Neumann]

Moin,

GIMP 2.4 will have rudimentary color management and while the
implementation is now basically ready, I am still not sure if we have
chosen the right defaults for color transformations and whether there is
the need to give the user more control over these parameters. I would
very much appreciate some advice here. But let me explain my questions
in more detail...

When opening an image file that has a color profile embedded, GIMP
offers to convert from the embedded profile to the configured RGB
workspace profile (which will be sRGB for most users). This conversion
currently happens with hardcoded parameters for rendering intent
(perceptual) and black point compensation (off). My questions are:

(1) Are these good default values or would you advice to change them?

(2) The rendering intent used for the display color correction can be
configured in the Preferences dialog. Would it make sense to reuse this
setting for the conversion when loading an image? Doing so would make
sure that, with display color correction enabled, the image would look
the same whether it is converted on load or not. I am currently
inclinded to follow this argumentation and to change the code
accordingly.

(3) Should the black point compensation setting be configurable somehow?
Currently we are using "off" all over the place and don't give the user
a chance to change that. Should we enable BPC for printer simulation? Do
we need to add configuration options for this? Would we need different
settings for display color correction and soft-proofing?

In advance, thanks for sharing your expertise.


Sven