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

[Elle Stone <ellestone ninedegreesbelow com>]

On 10/14/2014 06:54 AM, Øyvind Kolås wrote:
> > >So now all chromaticity-dependent editing operations will require a brand
> > >new "special "specifying"", unless the image is already an sRGB image.
> > >
> > >If you didn't intend to convert all images to unbounded sRGB for editing,
> > >there wouldn't be any reason to "special "specify"" roughly half of all the
> > >editing operations that you offer through the GIMP UI.
> Just like in an ICC based workflow images are converted to unbounded
> XYZ for editing? (they are not)

My apologies, I don't have a clue what you mean by what you just said.

But no, XYZ isn't a good color space for image editing, if that is what 
you are asking.

> The PCS used by a CMS is an
> implementation detail; where choices might have been XYZ, linear sRGB
> or some other linear RGB; of the preceding linear sRGB has nicer
> properties than any of the others.

The above sentence confuses concepts: The babl architecture might 
require that images to be converted to and from unbounded linear gamma 
sRGB. That doesn't mean babl is a CMS. And it doesn't mean unbounded 
linear gamma sRGB has been turned into a PCS.

To convert images to and from unbounded linear gamma sRGB, you MUST pass 
through XYZ. XYZ is the PCS.

Let's cut to the chase:

Are you planning on converting non-sRGB images to unbounded linear gamma 
sRGB? Yes or no?

If yes, are you intending that at least some editing will be done on the 
image while it's encoded using sRGB primaries? Yes or no?


With respect,
Elle Stone