Bug 413074

Summary: Gwenview does color management incorrectly if PNG has alpha channel
Product: [Applications] gwenview Reporter: Tyson Tan <tysontanx>
Component: generalAssignee: Gwenview Bugs <gwenview-bugs-null>
Status: RESOLVED FIXED    
Severity: normal CC: alex.kdebugzilla, idontfeelcomfygivingyoumyemail, nate
Priority: NOR    
Version First Reported In: 19.08.2   
Target Milestone: ---   
Platform: Other   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:

Description Tyson Tan 2019-10-17 08:32:02 UTC 
In a color managed workflow, when a PNG file has alpha channel, Gwenview renders the picture's color incorrectly. On a standard gamut sRGB display the differences might be hard to see, but on a wide-gamut display, the color shift is difficult to overlook. In the same environment, Gwenview displays PNG without alpha channel and JPGs with proper color management. I will attach test images I used later.

The definition of a "color managed workflow" here:
1) the display has been calibrated and profiled
2) the display's ICC profile (product of step 1) has been assigned properly in colord-kde
3) Krita, Firefox, Chromium are all doing color management correctly.
4) the picture was exported by Krita with "Embed sRGB profile" option checked.
Comment 1 Tyson Tan 2019-10-17 08:38:19 UTC 
https://www.dropbox.com/s/541v16df3a20vwj/electrichearts_20190929A_Skye_a.png?dl=0

This is a test PNG image with alpha channel. When opened by Gwenview on a wide-gamut display, the goose's beak looks over-saturated.

https://www.dropbox.com/s/541v16df3a20vwj/electrichearts_20190929A_Skye_a.png?dl=0

This is the same picture without alpha channel. When opened by Gwenview on a wide-gamut display, it looks the same as on a standard gamut display.
Comment 2 Tyson Tan 2019-10-17 08:39:32 UTC 
https://www.dropbox.com/s/lcemt5w1f2f8d7y/electrichearts_20190929A_Skye_b.png?dl=0
Sorry, this is the one without alpha channel. I copied the wrong URL.
Comment 3 A Linux User 2025-08-19 19:27:14 UTC 
Thank you for the bug report. Unfortunately we were not able to get to it yet. Can we ask you to please check if this is still an issue with Gwenview 25.08.0 (the latest released version)?
Comment 4 Tyson Tan 2025-08-20 01:36:50 UTC 
I think it has been fixed.