[Openicc] XICC specification draft

[Craig Ringer]

On Fri, 2005-06-24 at 11:44 -0400, Ben Guthro wrote:
> ...but we should at least ask the question - what does a color profile
> mean for a remote display?
>
> A color profile should be tied to the hardware for which it was
> profiled, should it not? If you measure the gamma response of a
> display, and create a color profile around this response, and set the
> X atom, then connect remotely from a different set of hardware - the
> gamma response of that hardware might be entirely different than the
> one which it was originally profiled...in which case the profile would
> make the colors look incorrect.

That's exactly why using an X server atom is such a good solution. The
atom is stored by the X server - so wherever your programs are
executing, they get the colour profile of the display they're being
displayed on.

I can set a colour profile on my desktop, and a different one on my
laptop. If I execute a program on my desktop and display it on my laptop
using the network transparency of X11, it'll be talking to
the /laptop's/ X server and thus will get the laptop's colour profile
when it asks the X server for a colour profile. No problem here.

> While I do see remote usage as important - how important is remote
> color management?

If we have colour management being integrated into more and more apps -
such as EoG - then it'd be ideal to have that work consistently. I think
it's strongly desirable for apps to be able to use colour management
easily and transparently. It's not done currently partly because it's
been too darn hard - but it's getting easier all the time with the work
being done in the area, including quite a bit being done by the people
on this list.

I don't think "just doesn't work for remote displays" is an acceptable
answer in the UNIX/X11 world, anyway.

Call me insane, but one of my goals at work is to be able to use desktop
publishing apps on /thin clients/ for some of our users. I see no reason
why the advertising dep't shouldn't be able to open last week's ad,
change a price, and save it. I'm not sure I see why they should have to
ask Production to save a PDF copy just so they can preview it, either,
or why the should be unable to get accurate colour* just because their
display happens to be remote. None of these tasks are all that
demanding, it's not like they'd be doing video editing or manipulating
big images.

>  If initial releases of this spec say that remote windows remain
> unmanaged, this might be acceptable.

As above, that shouldn't be required.

* within the limitations imposed by relatively hastily calibrated and
office-quality not pro-quality displays, of course.

--
Craig Ringer