Re: [Gimp-developer] New Image/Color Management option

[Elle Stone <ellestone ninedegreesbelow com>]

On 06/04/2016 11:53 AM, Alexandre Prokoudine wrote:
> On Sat, Jun 4, 2016 at 6:17 PM, Gez wrote:
>
> > That's what Elle has been fighting against for a long time, and that's
> > still the problem.
>
> Fighting? Against? This is a community project. We don't fight here,
> we make stuff happen. Althought it looks like you really, really want
> to fight.
>
> "Support for RGB working spaces other than sRGB" is already in the
> roadmap, which one might attribute to Elle's eloquence.

Just to set the record straight regarding the outcome of my "eloquence":

Beginning in April 2014, and with help from several other people, I 
spent an enormous amount of time and effort testing and documenting the 
inadequacies of the babl architecture that uses unbounded sRGB as a 
universal working space and pseudo-PCS: 
http://gimp.1065349.n5.nabble.com/template/NamlServlet.jtp?macro=search_page&node=2&query=unbounded+sRGB&days=0

The net result of my long campaign to persuade the babl/GEGL/GIMP devs 
to abandon their long-planned sRGB-only architecture is:

1. A few paragraphs in the babl roadmap: 
https://git.gnome.org/browse/babl/tree/docs/roadmap.txt

2. A promise that "eventually" GIMP will support editing in color spaces 
other than sRGB: http://wiki.gimp.org/wiki/Roadmap

This is a pitifully small return for the amount of effort I and others 
have put into trying to turn GIMP around so it can become the amazing 
image editor that it would already be if the misguided babl architecture 
had been abandoned back in 2014, as it should have been.

For the foreseeable future:

* GIMP 2.9/2.10 is in fact an "unbounded sRGB only image editor": 
http://ninedegreesbelow.com/photography/unbounded-srgb-as-universal-working-space.html

* GIMP code is still written around the misguided notion of "sRGB as 
PCS": 
http://gimp.1065349.n5.nabble.com/Don-t-make-an-architectural-mistake-based-on-a-groundless-premise-td43812.html#a43875

I feel partly responsible for the current sad state of GIMP code because 
in the long discussion of the babl architecture the question came up 
concerning whether the babl flips should also be abandoned. I said they 
could be useful. I didn't realize just how invasively they would spread 
through the GIMP code base.

In retrospect, the sensible thing to do is to completely remove all 
traces of the babl flips from babl/GEGL/GIMP. If this is done, then when 
a person wants to edit a linear gamma image, all they have to do is 
convert the image to a linear gamma ICC RGB working space. The babl 
flips aren't needed for linear gamma image editing.

And then institue "per layer/layer group" ability to flip to a 
user-specified TRC for the very few cases where an informed imager 
really does want or need to edit nonlinear RGB.

Uninformed GIMP users would still have the option to edit in the regular 
sRGB color space as they already do.

Best,
Elle
--
http://ninedegreesbelow.com
Color management and free/libre photography