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

[Elle Stone <ellestone ninedegreesbelow com>]

On 04/30/2015 10:00 PM, Gez wrote:
> I think that allowing that would complicate the UI and the the tools
> themselves, as all of them should have both paths available.

All the tools need to provide the user with the ability to choose linear 
or perceptual RGB at will, at the user's discretion. And the tools need 
to inform the user what's being used at any given point, for any given 
operation.

If having a less complicated UI is more desireable than giving the user 
the ability to choose whether any given instance of an operation is done 
using linear or perceptual RGB, then the babl flips should be 
permanently removed from babl.

> A better solution would probably have to wait until proper
> no-destructive editing is finally implemented, and operations are
> visualized as a stack/chain/whatever.

And that will mean putting user control over what happens to their RGB 
data off for how long? how many years will GIMP users not be able to 
control what's done to their RGB data?

This is a color managment issue. It's fundamentally important. GIMP 
shouldn't make decisions like "use linear here and perceptual there", 
other than to offer the user good defaults.

> I mean, instead of putting toggles on EVERYTHING, why not adding a tool
> that says "from this point, the following operation/s will be performed
> in linear/perceptual gamma"?

Because there is no "from this point" in RGB image editing. It is not 
the case that "until point X use linear RGB" and "after point Y use 
perceptual RGB" makes any sense. EVERYTHING NEEDS A TOGGLE. It's an 
operation by operation decision. The user has a right and the *need* to 
know and be able to control what's being done with the user's own RGB data.

GIMP should NOT make such decisions behind the user's back, forcing the 
user to use linear RGB in one place and perceptually uniform RGB in 
another place without so much as a by your leave. GIMP can't know the 
user's technical purposes. GIMP can't know the user's artistic 
intentions. Right now the babl flips are a hobble, not a help.

> People used to node-based UIs will understand exactly what I mean.
> The difference would be that only users who need the toggle will add an
> operation that makes the switch when it's required. The UI will remain
> lean, without extra options that could potentially confuse less advanced
> users.

ALL users need the toggles. Not all users might want to take advantage 
of the toggles. That's what good default settings are for.

The GIMP UI already is complicated. Saying "let's not complicate it" is 
like shutting the barn door after the cows are already out. This is a 
place where GIMP MUST have complications because user control over their 
own data is at stake.

If not complicating the UI is a design goal for GIMP, well, you all have 
failed spectacularly.

Color management is complicated. GIMP should enable the user, not 
constrain the user. The babl flips should either be put 100% under the 
user's control, or else be removed from GIMP. If the toggles aren't your 
cup of tea, please find another way to give 100% control to the user. Or 
else get rid of the babl flips.

Best,
Elle