[Gimp-developer] Converting 8-bit integer color palettes to floating point

[Elle Stone <ellestone ninedegreesbelow com>]

Hi All,

In these two GIMP bug reports:

* Support for high bit depth RGB (and LCH?) color palettes for painting
https://gitlab.gnome.org/GNOME/gimp/issues/1328

* Add support for Swatchbooker's SBZ colour palette format
https://gitlab.gnome.org/GNOME/gimp/issues/2011

are discussions regarding either *converting* GIMP code to use 
SwatchBooker for high bit depth color palettes, or else *keeping* GIMP 
GPL palette code (updated to use floating point), and also adding 
support for importing/exporting SwatchBooker color palettes.

Here's the current git repository for SwatchBooker, maintained by 
Olivier Berten: https://github.com/olivierberten/SwatchBooker

Adding support for importing/exporting SwatchBooker color palettes seems 
like a really good idea for reasons given by "Christoph S" in bug #2011.

But converting all GIMP color palette code to use SwatchBooker maybe 
isn't such a good idea given the reality that maintainers of various 
free/libre projects do come and go as their lives place various demands 
on time and energy.

Anyway, I did write some barebones working code to convert GIMP color 
palette code from 8-bit integer to floating point. Details and the 
patches are in bug #1328.

My floating point palette code isn't finished. Well, it's sufficiently 
finished for my own needs. But I drastically simplified the palette code 
by removing everything except the core code for opening and saving a 
palette to/from a GPL file. Otherwise I'd still by trying to figure out 
which of the many the palette-related files/functions/variables does what.

If the GIMP team reaches a consensus to *keep* GIMP's GPL palette code 
and just update it to be floating point (and of course add support for 
importing/exporting SwatchBooker assets) - instead of *replacing* GIMP's 
GPL palette code with SwatchBooker - then I'd go ahead and try to add 
back into my working patch the various non-core palette functions that I 
removed to make it easier to figure out the core palette code.

Best regards,
Elle