Re: [Gimp-developer] [Gegl-developer] babl roadmap

[Elle Stone <ellestone ninedegreesbelow com>]

On 10/17/2014 07:08 AM, Øyvind Kolås wrote:
> On Fri, Oct 17, 2014 at 1:06 PM, Elle Stone
> <ellestone ninedegreesbelow com> wrote:
> > On 10/17/2014 06:59 AM, Øyvind Kolås wrote:
> > > As a former researcher at a national color science laboratory, and a
> > > major contributor to babl and GEGL; I probably have no idea about
> > > these things – and how the spectral data in named color ICCv4 profiles
> > > might be used.
> > >
> > > https://www.youtube.com/watch?v=vKpaXu87Coo
> > >
> > > /Ø
> > Nobody doubts your intelligence, acumen, or accomplishments. Not even me.
>
> Then what is the purpose of continuing to endlessly perpetuate this
> discussion, asking people to read about spectral color management,
> when our roadmaps barely have good colorimetric management in scope?
> For the sake of argument alone?
>

I did not ask people to study spectral color management. I did ask 
people to realize that the ICC profile specs are changing. In 
particular, D50 will no longer be the only profile illuminant.

The point of this "endless discussion" is that unbounded sRGB is a 
singularly bad way to forcibly recast the user's RGB data for RGB image 
editing.

The code for converting to unbounded sRGB isn't yet in place.

At present, to get right results from babl/GEGL/GIMP, it would suffice 
to replace hard-coded sRGB Y and XYZ with UserRGB's Y and XYZ, and 
correct the babl code that converts to XYZ.

And of course it should be easy for the artist to switch at will between 
perceptually uniform and linear RGB.

For the very few RGB editing operations that really must be done using 
the sRGB primaries, write special code as appropriate and label the 
operations in the UI as "sRGB only" so the user knows what's happening.

The babl roadmap lays out a plan to complicate the existing code, 
apparently only to turn around and straighten it out again.

With respect,
Elle Stone