Bug 513958

Summary: Saturation slider granularity too small
Product: [Applications] digikam Reporter: Milan Zamazal <pdm>
Component: Plugin-Editor-HSLAssignee: Digikam Developers <digikam-bugs-null>
Status: RESOLVED FIXED    
Severity: normal CC: caulier.gilles, metzpinguin
Priority: NOR    
Version First Reported In: 8.8.0   
Target Milestone: ---   
Platform: Appimage   
OS: Linux   
Latest Commit: https://invent.kde.org/graphics/digikam/-/commit/b659a2e0b79685fb290df77f9c84a3657a571074 Version Fixed/Implemented In: 9.0.0
Sentry Crash Report:

Description Milan Zamazal 2025-12-29 17:20:28 UTC 
SUMMARY

The saturation slider in HSL Correction in my environment has the range of values -100..100, with the step 0.01. The step is very small, it makes adjusting saturation by pressing the arrow buttons or by using a mouse wheel unusable. Changing the saturation value by 1.0 is hardly noticeable, changing it by 0.01 makes no sense.

STEPS TO REPRODUCE
1. Open the image editor.
2. Invoke HSL Correction.
3. Try to set the saturation adjustment value to e.g. 10 using the arrow buttons or a mouse wheel.

OBSERVED RESULT

It takes 1000 clicks to reach the value 10.

EXPECTED RESULT

Let's say 10 clicks (using increments of 1) would be much better.

SOFTWARE/OS VERSIONS
Operating System: Debian GNU/Linux 13
KDE Plasma Version: 6.3.6
KDE Frameworks Version: 6.13.0
Qt Version: 6.8.2

ADDITIONAL INFORMATION
Comment 1 Maik Qualmann 2025-12-29 17:36:46 UTC 
Can't you just drag the slider, or simply click in the row with the left mouse button and change the value? Please take a screenshot.

Maik
Comment 2 caulier.gilles 2025-12-29 17:41:40 UTC 
Maik,

I suspect that Milan talk about the step used to change a value.

Note: Here dragging a slider work perfectly under Linux.

Gilles
Comment 3 Milan Zamazal 2025-12-29 19:02:22 UTC 
Indeed, I talk about the step. 
Yes, I can use the slider and it works. But for fine adjustments, using a mouse wheel or the slider buttons would be more comfortable. If only the step was a more reasonable value than 0.01, which is too small (assuming it's not specific to my environment, I suppose adjusting saturation to small values like e.g. 0.05 has no visible effect anywhere).
Comment 4 Maik Qualmann 2025-12-29 19:07:44 UTC 
Git commit b659a2e0b79685fb290df77f9c84a3657a571074 by Maik Qualmann.
Committed on 29/12/2025 at 19:06.
Pushed by mqualmann into branch 'master'.

change granularity to 0.1 from HSL plugin sliders
I didn't choose a value of 0.5 or 1.0 because
0.5 already represents visible steps.
FIXED-IN: 9.0.0

M  +1    -1    NEWS
M  +3    -3    core/libs/dimg/filters/hsl/hslsettings.cpp

https://invent.kde.org/graphics/digikam/-/commit/b659a2e0b79685fb290df77f9c84a3657a571074
Comment 5 Maik Qualmann 2025-12-29 19:09:51 UTC 
One more note: it is also possible to directly enter a value by right-clicking in the slider.

Maik
Comment 6 Milan Zamazal 2025-12-29 19:15:11 UTC 
Great, thanks!
(Thank you also for the tip; I know it's possible to enter the value by using a keyboard but switching between a keyboard and a mouse is usually cumbersome.)