Bug 136770

Summary: Hotpixel tool doesn't interpret black image correctly with stuck pixel
Product: [Applications] digikam Reporter: Simon Oosthoek <kdebugs>
Component: Plugin-Editor-GmicQtAssignee: Digikam Developers <digikam-bugs-null>
Status: RESOLVED FIXED    
Severity: normal CC: caulier.gilles, ugarro
Priority: NOR    
Version: 0.9.0   
Target Milestone: ---   
Platform: Ubuntu   
OS: Linux   
Latest Commit: Version Fixed In: 8.4.0
Sentry Crash Report:

Description Simon Oosthoek 2006-11-03 13:05:34 UTC 
Version:           0.9.0 beta 3 (using KDE KDE 3.5.5)
Installed from:    Ubuntu Packages
Compiler:          gcc (GCC) 4.1.2 20060928 (prerelease) (Ubuntu 4.1.1-13ubuntu5) 
OS:                Linux

I have a camera with one stuck pixel (red). I tried to use the hotpixel plugin to fix it, but it doesn't interpret the black image correctly.

It would be much easier if I could simply indicate the hot pixel manually and store that information in the program/plugin configuration. If required, I can provide the black image (it's rather big, even in jpg, due to the noise)
Comment 1 Simon Oosthoek 2006-11-03 13:07:00 UTC 
The KDE packages are from ubuntu, but I compiled the digikam 0.9.0 beta 3 sources (the ubuntu edgy packages have a conflict with showfoto and digikam)
Comment 2 Andi Clemens 2008-10-19 03:21:08 UTC 
Is this still valid? Unfortunately I can't test it right now.
Comment 3 caulier.gilles 2008-12-06 18:08:00 UTC 
Unai, 

Are you seen this report ?

Gilles Caulier
Comment 4 Unai Garro 2008-12-06 21:18:02 UTC 
Thanks for forwarding, Gilles, I had missed this report indeed. 

Stuck pixels and hot pixels are treated equally, so it should still work. Are you sure you used the same image size and format for the black image as for the photograph image? Can you attach the black image and a sample photo here, so that we can confirm the bug?

If sizes match, might be that the tool sees more hot pixels than your eye. The algorithm for searching hot pixels is usually much more sensitive than the eye locating hot pixels, so it may show you more hot pixels than your eye can see. Most of the times, there's more than one pixel surrounding that are "hot".  Maybe the sensitivity of the algo can be made adjustable to suit the user's taste?

And well, I agree obviously that, manually selecting HP could be an interesting feature too.
Comment 5 caulier.gilles 2011-12-17 19:02:19 UTC 
Unai,

Did you manage this entry to fix it ?

Gilles Caulier
Comment 6 caulier.gilles 2020-08-07 13:43:11 UTC 
Simon,

Can your provide a test image to improve the Hot Pixel tool.

Note this one will be also included in BQM to be able to batch process images.

Thanks in advance

Gilles Caulier
Comment 7 caulier.gilles 2024-05-22 07:21:57 UTC 
digiKam Image Editor GMicQt tool propose a Hot Pixel Filter which do not requires a black frame template to fix photo. Hot pixels is auto-detected in image :

https://i.imgur.com/KpHbDdp.png

Gilles Caulier