Kelly Martin <[EMAIL PROTECTED]> wrote:
> Someone would have to develop the profiles.  The way Photoshop
> does it is by buying printers and doing test prints and gathering
> colorimetric data.  The GIMP developers are short on people who
> have access to colorimetry labs, not to mention lots of printers.
> A lot of the processes that go into prepress are tied up in patent
> and trade secret law.  Getting those processes into the GIMP will
> be no easy task.

This is a furphy.  Generating the profiles is quite different from
using them.  There are existing libraries (e.g. lcms) to convert
between colour spaces (defined by profiles) and there's even a Gimp
plug-in to do this.  There is even software for generating profiles
for printers/scanners/etc (not part of the Gimp, but it doesn't have
to be).

For accurate colour work you typically need to profile your own
devices, as each has a slightly different colour response (e.g. for
a printer it depends on the driver settings, the ink, and the paper
choices).  Monitors in particular constantly change their behaviour
and need to be reprofiled regularly.  Good print labs profile their
devices and provide the profiles to their clients.
It's not up to the Gimp to generate profiles, it's up to the Gimp
to use them.

Unfortunately Gimp has a way to go before it has a concept of your
monitor colour space (and dynamically converting displayed images
into that colour space) and a colour space for each image.  This
is something that Photoshop (and most of the other Adobe software)
does very well.  The Gimp has a plain model where there is only one
colour space: your monitor's.  Everything is dealt with as just RGB
(disregarding the HSV/etc composition/decomposition feature) and
sent to your monitor as-is.  I think a more-sophisticated model is
required to support a colour-managed workflow (and things like
16-bit support, CMYK, L*a*b, etc are just part of that).

Other projects like CinePaint (nee FilmGimp) are making progress
on this.  Hopefully the Gimp will catch up.  But I don't think
"patent and trade secret law" has much to do with it.
David Burren
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