Re: [Gimp-developer] Configurable target selection by the "Auto" button on the Levels dialog

["Liam R. E. Quin" <liam holoweb net>]

On Sun, 2015-06-14 at 19:05 -0300, Rodrigo Severo wrote:
> Hi,
>
>
> The "Auto" button on the Levels dialog has a fixed behaviour today 
> (which I don't know exactly which is).

The source code is available -- essentially it stretches contrast in 
each R, G, B channel separately. If you press Auto and then open as 
curves, you can see. The end points are, however, a few percent in 
from the ends, limiting its usefulness in a professional setting.

> Its behaviour should be configurable by the user.
The point of it is that it "just works". An auto button should not be 
configured.

I think really what you are asking for is a "stretch contrast" filter 
that has configurable black and white points.

Note that you can already configure the black and white points in 
levels using the eye dropper.


> The user interface for this functionality could be accessed by the 
user double clicking the "Auto" button.

That would be a "no" :-)  There aren't any other buttons that behave 
differently when you double-click on them (and actually for good 
reason, as no-one would ever guess it, and because it would mean every 
button would have to wait to see whether the user double-clicked 
before doing anything, giving a UI feeling of slowness.

I'm supportive of being able to set the levels/auto clipping 
percentage, perhaps in the Colours/Map/Stretch Contrast GEGL filter.

Liam

-- 
Liam R. E. Quin <liam holoweb net>
http://www.FromOldBooks.Org/