Re: [Gimp-developer] GIMP useability - choosing linear vs perceptually uniform RGB

[Elle Stone <ellestone ninedegreesbelow com>]

On 05/02/2015 03:39 PM, Øyvind Kolås wrote:
> > I'm not entirely sure what you are proposing or how it could be implemented
> > >in the UI. Is this what you mean?
> > >
> > >1. Make a list of all RGB editing operations that are provided by GIMP.
> > >
> > >2. Decide for each operation whether it should be done using linear or
> > >perceptual RGB and set that as the default way the operation will be done.
> > >
> > >3. Figure out which RGB operations "legitimately" should also be allowed to
> > >be done using the opposite choice from what the developers decided.
> > >
> > >4. For the operations for which users can choose other than the default, do
> > >what? I can think of two possibilities:
> > >
> > >      i. Make an entirely new RGB editing operation. For example
> > >Curves-linear and Curves-perceptual, Gradient-linear and
> > >Gradient-perceptual, Soft-light-blend-linear and
> > >Soft-light-blend-perceptual, and so forth. Then stuff these new editing
> > >operations into the menu.
> > >
> > >      ii. Put an override button on the UI for the particular layer blend
> > >mode or tools/operation UI. But you said specifically said you don't want to
> > >put additional, possibly confusing buttons in the UI.
> > >
> > >Is above close to what you are envisioning?

> Nope, I envison the operator of GIMP to do a*separate*  action before
> a particular action to override the default/sane pixelformat for, and
> then a*separate*  action afterwards.

What does this separate action before and after the RGB operation look 
like in the UI?

You are saying that this "three click" approach is better from a user 
viewpoint than simply having a button on the Curves UI to switch between 
the clearly marked default and the alternative?

> For some particular operations
> more direct ways of achieving it can be provided if it is common
> tasks; like for instance adding the ability to do curves/levels in CIE
> Lab instead of RGB; but in general the sledge hammer to offer the
> operator this ability is additional actions.

So if users are allowed to choose between perceptual and linear for RGB 
Curves, there might be two Curves operations, each with their own entry 
in the UI, one for linear RGB and one for perceptual RGB? How is this a 
cleaner UI than one Curves dialog with a button?

Or do you mean one UI entry for linear RGB Curves and one for CIELAB 
Curves? CIELAB Curves is not a substitute for RGB Curves, though CIELAB 
Curves would be an excellent addition to GIMP.

What about layer blend modes? Will there be two layer blend modes, one 
for linear and one for perceputal, for those layer blend modes for which 
the devs decide the user should be given a choice? The "button on the 
layer or tool interface" approach does seem like a cleaner solution from 
the UI point of view.

Best,
Elle