GNOME Bugzilla – Bug 723213
colors/levels/auto is broken for high bitdepth images
Last modified: 2016-12-27 14:34:02 UTC
Created attachment 267477 [details]
Sample image for reproducing the problem easily
Try opening the enclosed image and open the colours/levels dialogue, then press the Auto button.
In 8-bit precision it looks OK.
Convert the image to higher precision and the result is bright yellow, which does not seem useful.
I'm not sure if the problem is in the conversion or in levels/auto, but I think in levels/auto. Colours/Auto/White Balance has the same problem.
This *should* fix it, but...
Author: Michael Natterer <email@example.com>
Date: Thu Jan 30 00:19:37 2014 +0100
Bug 723213 - colors/levels/auto is broken for high bitdepth images
Port gimp_levels_config_stretch_channel() to histograms with
variable number of bins. Still behaves differently for different
bit depths tho.
These issues seem to be gone in master - and with further fixes/work in linear color space the result are even closer to my expectation.