Created attachment 133137 [details] How the same image file is displayed differently in different apps SUMMARY After upgrading to Kubuntu 20.10 I have this strange problem of displaying colors of an image file edited in Krita differently in different apps. I was using Krita version 4.3 under Kubuntu 20.04 when I didn't have such a problem. Using Krita versions 4.3 or 4.4 makes no difference under Kubuntu 20.10. I think probably this problem has nothing to do with Krita. For instance, most recently, I wanter to change the default icon of Zoom app, applying the same light blue color (#529dfe) to a simpler PNG image with only a video camera symbol in the center, surrounded by a transparent area, and then an outline border. The resulting image looked OK firstly in Krita, and in ShowFoto as well as web browsers Vivaldi and Falkon. However, the light blue color of the outline border and the video camera symbol in the center is displayed as dark gray with a hint of blue (#57617a) in Dolphin, KolorPaint, Ksnip Screenshot Tool, XnView and gImageReader. Sometimes the colors are not displayed as expected in ShowFoto as well. STEPS TO REPRODUCE 1. Open/View the attached image file "Zoom-edited.png" in various apps listed above. 2. Or open the attached image files "Zoom.png" and "zoom-new.png" in Krita, fill the space inside video camera symbol, select the light blue color (#529dfe) in "Zoom.png", apply it to the black areas (outline border and video camera symbol) in "zoom-new.png", save it as "zoom-edited.png", and then view it in various apps listed above. OBSERVED RESULT The light blue color (#529dfe) applied and saved in Krita is displayed as dark gray with a hint of blue (#57617a) in Dolphin and some other apps, while it's displayed correctly in some others like ShowFoto. EXPECTED RESULT The image files edited and saved in Krita should be displayed in the same way in all applications. SOFTWARE/OS VERSIONS Operating System: Kubuntu 20.10 KDE Plasma Version: 5.19.5 KDE Frameworks Version: 5.74.0 Qt Version: 5.14.2 ADDITIONAL INFORMATION
Created attachment 133138 [details] The PNG file which is displayed differently in different apps
Created attachment 133139 [details] Original image file used for selecting color
Created attachment 133140 [details] The PNG file used to create a new icon
Sorry, I've just discovered that this is probably a Krita bug.
I've just discovered that this problem occurs when saving a PNG file with the option "Save as HDR Image (Rec. 2020 PQ)" selected. I think I've decided to select this option at some point perhaps expecting a "better quality". ;-)
Well, Linux simply doesn't support HDR images at all.
Please read the manual on working with colors: https://docs.krita.org/en/general_concepts/colors.html . This is not a bug, it's simply the way things work.
(In reply to Boudewijn Rempt from comment #7) OK. Thanks. Sorry, I've solved this problem in the process of bug-reporting. ;-) But I think it might perhaps still be considered as a bug that this option is not greyed out or excluded in the Linux version because it is unusable and even causes such such strange problems.