Bug 509633 - Effects -> Color Effects: Lut3D stopped working
Summary: Effects -> Color Effects: Lut3D stopped working
Status: RESOLVED DOWNSTREAM
Alias: None
Product: digikam
Classification: Applications
Component: ImageEditor-Plugins (other bugs)
Version First Reported In: 8.7.0
Platform: Other Linux
: NOR normal
Target Milestone: ---
Assignee: Digikam Developers
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2025-09-18 09:49 UTC by Marcus Hardt
Modified: 2025-09-24 09:50 UTC (History)
2 users (show)

See Also:
Latest Commit:
Version Fixed/Implemented In: 8.8.0
Sentry Crash Report:


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Description Marcus Hardt 2025-09-18 09:49:12 UTC
SUMMARY
I've upgraded from 8.6.0 to 8.7.0.  Since then, Lut3Ds do not show any effect. Neither the preview, nor apply, nor save.


STEPS TO REPRODUCE
1. Edit an image (F4)
2. Open the "color effects" tool
3. In the tool choose from the dropdown "Type": "Lut3D"
4. Pick a LUT, make sure intensity is not "0%"
5. Observe there is no effect applied, by moving mouse on image and on tool.

OBSERVED RESULT


EXPECTED RESULT


SOFTWARE/OS VERSIONS
Windows: 
macOS: 
(available in the Info Center app, or by running `kinfo` in a terminal window)
Linux/KDE Plasma: 
KDE Plasma Version: 
KDE Frameworks Version: 
Qt Version: 

ADDITIONAL INFORMATION
Comment 1 Maik Qualmann 2025-09-18 10:24:38 UTC
The Lut3D plugin works without issues here. Which digiKam version are you using?
If it's an Ubuntu Snap package, use our AppImage.

Maik
Comment 2 Marcus Hardt 2025-09-18 13:02:00 UTC
I use the debian package installed locally. In case it matters: I don't have KDE as a desktop.

The exact version is: 4:8.7.0-1
Comment 3 Maik Qualmann 2025-09-18 16:15:42 UTC
Are any binary digiKam packages missing from the installation? Typically, there should be a folder "/usr/share/digikam/data/lut3d" with PNG files. Please check.

Maik
Comment 4 Maik Qualmann 2025-09-18 16:26:53 UTC
Wait, they're now webp images. The most likely cause is that you don't have the KImageFormat plugins installed. This plugin is required for QImage to load these images.

Maik
Comment 5 Marcus Hardt 2025-09-19 09:33:04 UTC
I just installed:

kimageformat-plugins: 5.116.0-1
and
kimageformat6-plugins: 6.13.0-2

But nothing changed.

A working workaround is to convert the webp images to png.
Comment 6 caulier.gilles 2025-09-19 09:49:14 UTC
As i know the Webp support must be compiled in Qt core. KImageFormat do not have an extra plugin code for Webp, all is delegate to the Qt core.

List of codec source codes from KImageFormat (no webp stuff):

https://invent.kde.org/frameworks/kimageformats/-/tree/master/src/imageformats?ref_type=heads

README from KImageFormat (no webp stuff):

https://invent.kde.org/frameworks/kimageformats/-/blob/master/README.md?ref_type=heads

So, when Qt is configured before compiling, libwebp-dev must present and detected.

Best regards

Gilles Caulier
Comment 7 caulier.gilles 2025-09-19 09:50:09 UTC
Doc from Qt about image formats supported (webp is present):

https://doc.qt.io/qt-6/qtimageformats-index.html

Gilles Caulier
Comment 8 Maik Qualmann 2025-09-19 11:19:08 UTC
Okay, WebP is part of Qt, and we've actually converted many PNG graphics to WebP. But then you shouldn't see the splash screen images, for example?

Maik
Comment 9 Marcus Hardt 2025-09-20 05:04:14 UTC
Yes, I also do not see any splash screen.
Comment 10 Maik Qualmann 2025-09-20 06:24:42 UTC
Ok, you need to report the problem to Debian, they need to build Qt with Webp support.

Maik
Comment 11 Marcus Hardt 2025-09-24 09:50:02 UTC
Filed upstream as https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1116194