After an evaluation, GNOME has moved from Bugzilla to GitLab. Learn more about GitLab.
No new issues can be reported in GNOME Bugzilla anymore.
To report an issue in a GNOME project, go to GNOME GitLab.
Do not go to GNOME Gitlab for: Bluefish, Doxygen, GnuCash, GStreamer, java-gnome, LDTP, NetworkManager, Tomboy.
Bug 723213 - colors/levels/auto is broken for high bitdepth images
colors/levels/auto is broken for high bitdepth images
Status: RESOLVED FIXED
Product: GIMP
Classification: Other
Component: General
git master
Other All
: Normal normal
: 2.10
Assigned To: GIMP Bugs
GIMP Bugs
Depends on:
Blocks:
 
 
Reported: 2014-01-29 04:00 UTC by liam
Modified: 2016-12-27 14:34 UTC
See Also:
GNOME target: ---
GNOME version: ---

Attachments
Sample image for reproducing the problem easily (799.60 KB, application/x-gnome-theme-package)
2014-01-29 04:00 UTC, liam 		Details

Description liam 2014-01-29 04:00:45 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.
Comment 1 Michael Natterer 2014-01-29 23:21:46 UTC 
This *should* fix it, but...

commit fcecafa4797d66fb4b4e657ce70598a961991fc7
Author: Michael Natterer <mitch@gimp.org>
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.
Comment 2 Øyvind Kolås (pippin) 2016-12-27 14:34:02 UTC 
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.