Re: [Gimp-developer] Update on my Gimp color management coding efforts

[Elle Stone <l elle stone gmail com>]

On 11/10/12, Michael Natterer <mitch gimp org> wrote:
> On Sat, 2012-11-10 at 15:17 -0500, Elle Stone wrote:
>> On 11/8/12, Jon Nordby <jononor gmail com> wrote:
>> > Has your work on replacing the deprecated functions found its way into
>> > git master?
>>
>> No. With Mitch's help I did made a patch file (which might be out of
>> date by now, as Gimp keeps changing):
>> http://ninedegreesbelow.com/temp/gimp-lcms-deprecated.html#patch
>
> Indeed :) I cleaned up that patch to match GIMP's coding style,
> fixed some little things, and attached it to:
>
> https://bugzilla.gnome.org/show_bug.cgi?id=662739
>
> Let's continue the patching and patch discussion in this bug.
> I also added a comment on the patch there.
>
>> > * Change the lcms-based conversion (modules/display-filter-lcms.c)
>> > from being a generic display filter to be something that takes a
>> > GeglBuffer in and blits into a cairo_surface_t.
>> > * Change the display filter interface to accept a GeglBuffer instead
>> > of a cairo_surface_t. As gimp_color_display_convert_surface is public
>> > API, it should probably become a stub and be marked as deprecated. New
>> > interface could for instance be called
>> > "gimp_color_display_convert_buffer"
>> > * Adapt all the display filter operations (modules/display-filter-*.c)
>> > to the new interface and to working on 32bit floating point. If any of
>> > the operations are no longer useful, now would be the time to drop
>> > them.
>> > * In the use of the display filter stack (in
>> > gimp_display_shell_render), first let the filter stack operate on the
>> > GeglBuffer from the projection (or possibly a copy), and then pass it
>> > to the lcms-based color conversion, and then pass that to cairo.
>> > --
>> > Jon Nordby - www.jonnor.com
>> >
>>
>> I'm looking forward to taking another look at the monitor display code
>> path. Your suggestions sound very helpful.
>
> It does, but it's clearly step 2 (or step n). IMO we should first
> get the lcms plug-in right so the data GIMP is dealing with is
> correct in the first place.

I completely agree that getting the lcms.c plugin to work is the first
priority, though hopefully "n" is very close to 2.

By the end of this week I will have whittled my "to do" list down to
where Gimp color management is back near the top of the list, so I'll
be stopping by IRC more regularly. I think I understand your bug
report comment and can provide context.

Cheers,
Elle