Re: [Gimp-developer] [Gimp-user] Time to fork BABL and GEGL

[Mikael Magnusson <mikachu gmail com>]

On Mon, Nov 17, 2014 at 10:03 PM, Elle Stone
<ellestone ninedegreesbelow com> wrote:
> On 11/17/2014 10:46 AM, Simon Budig wrote:
> > Hi Elle.
> >
> > The following is my understanding, when pippin answers his answers have
> > more authority than mine.
>
>
> Hi Simon,
>
> I appreciate your answers, but the points you make aren't actually relevant
> to the questions that I wanted to ask Pippin. This is my fault. In an effort
> to clarify what I think he's saying, I seem to have just opened the door for
> more miscommunication.
> > Elle Stone (ellestone ninedegreesbelow com) wrote:
> > > Putting aside coding considerations that might affect other software that
> > > uses babl and GEGL, here's my understanding of your current plan for
> > > babl/GEGL/GIMP:
> >
> >
> > A slight preface here. I don't consider it important to focus on the
> > *storage* of the pixel data, as in the actual bulk memory for the pixel
> > data.
>
>
> If you choose to *store* the user's RGB data using chromaticities not of
> user's choosing, that suggests that you also intend to *edit* the user's RGB
> data using chromaticities not of user's choosing
>
> > > 1. Upon opening an image, the image will be converted to unbounded sRGB.
> >
> >
> > I don't think that this is decided yet, I actually consider it unlikely
> > at the moment. I think it might be more likely to have it sitting in
> > memory as userRGB.But again, this is an implementation detail, where I
> > assume that the floating point math is sufficiently precise to avoid
> > visible rounding errors.
>
>
> This is not just an implementation detail. The user has the right to control
> what RGB working space is used when performing RGB edits on the user's own
> RGB data.

The above two things are implementation details as Simon said. If you
don't understand this, then please don't write long articles full of
misinformation that get widely quoted. Your answers suggest you didn't
even understand what he said. Your argument is like saying it matters
if you store an integer in decimal or binary, and doing anything else
than the user input is definitely wrong, because there is no longer
any way to display it in this format.

Gegl stores pixels in memory in some format, it knows what format it
used. Gimp can display/edit pixels in some color space (specified by
the user). Gimp asks Gegl for pixels saying what colorspace it wants.
Gegl presents the pixels to Gimp. All is well. It doesn't matter how
the pixels are stored.

-- 
Mikael Magnusson