| Summary: | Png file with gamma show washed out colours | ||
|---|---|---|---|
| Product: | [Applications] gwenview | Reporter: | Raghavendra kamath <raghu> |
| Component: | general | Assignee: | Gwenview Bugs <gwenview-bugs-null> |
| Status: | RESOLVED FIXED | ||
| Severity: | normal | CC: | ancoron.luciferis, idontfeelcomfygivingyoumyemail, mafriki, phd, shibotto |
| Priority: | NOR | ||
| Version First Reported In: | 21.08.0 | ||
| Target Milestone: | --- | ||
| Platform: | Other | ||
| OS: | Linux | ||
| See Also: | https://bugs.kde.org/show_bug.cgi?id=465066 | ||
| Latest Commit: | Version Fixed In: | ||
| Sentry Crash Report: | |||
| Attachments: |
base png test file
Screenshot showing the wrong colours of the png file in gwenview The converted png file that I get from imagemagick this-image-is-displayed-too-bright-in-gwenview.png |
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Created attachment 140834 [details]
Screenshot showing the wrong colours of the png file in gwenview
Adding the screenshot which shows how gwenview shows the converted png file for me.
Created attachment 140835 [details]
The converted png file that I get from imagemagick
Also attaching the png file that is got from imagemagick command
This commit introduced the issue: https://invent.kde.org/graphics/gwenview/-/commit/ac47787 Just to make sure people don't think it's a specific ImageMagick export issue some 8bit PNGs exported from Photoshop suffer the same issue so it may be helpful to remove "imagemagick" from the title. *** Bug 447308 has been marked as a duplicate of this bug. *** *** Bug 450205 has been marked as a duplicate of this bug. *** The actual issue here is that gwenview (or Qt) interprets the gamma value incorrectly. ImageMagick (and other tools) set a default gamma of 2.2 for PNG's and/or other file formats that support this metadata. For the attached files, here's some metadata: test.png: Bit Depth : 8 Color Type : RGB with Alpha Compression : Deflate/Inflate Filter : Adaptive Interlace : Noninterlaced Pixels Per Unit X : 11811 Pixels Per Unit Y : 11811 Pixel Units : meters Image Size : 1800x2700 hires.png: Bit Depth : 8 Color Type : RGB Compression : Deflate/Inflate Filter : Adaptive Interlace : Noninterlaced Gamma : 2.2 <<< creating trouble for gwenview White Point X : 0.3127 White Point Y : 0.329 Red X : 0.64 Red Y : 0.33 Green X : 0.3 Green Y : 0.6 Blue X : 0.15 Blue Y : 0.06 Background Color : 255 255 255 Pixels Per Unit X : 11811 Pixels Per Unit Y : 11811 Pixel Units : meters Modify Date : 2021:08:19 10:24:04 Warning : [minor] Text chunk(s) found after PNG IDAT (may be ignored by some readers) Datecreate : 2021-08-19T10:23:53+00:00 Datemodify : 2021-08-19T08:57:54+00:00 Image Size : 1800x2700 You can "fix" the PNG's for gwenview usually with: `convert <input> -set gamma 2.2 <output>` ...which actually sets the PNG gamma value to 0.4545, since it's the inverse (and which is what gwenview should be doing). However, that breaks the image for almost any other viewer/browser/editor that interpret the gamma value, since they then are doing the color correction in the inverse way with the inversed value. Some background on why it is the way it is: https://www.cambridgeincolour.com/tutorials/gamma-correction.htm Created attachment 146774 [details]
this-image-is-displayed-too-bright-in-gwenview.png
I think this should be a 15-minute bug. Browsing images is a very typical use case, and hitting this bug does not leave a good impression. I couldn't reproduce this bug in KDE neon: Gwenview 22.03.70 (KDE neon dev packages), 22.03.70 (git master), 21.12.2 (git tag), 21.08.0 (git tag) KF 5.91.0 and Qt 5.15.3 However it is reproducible in Kubuntu 21.10: Gwenview 21.12.2, KF 5.91.0 and Qt 5.15.2 So, was it fixed in Qt 5.15.2 -> 5.15.3? @phd Yes, it looks like a Qt bug to me as well, since the code changes that supposedly introduced this regression only incorporate color correction using Qt interfaces. Still happening in Ubuntu 22.04 with Gwenview 22.04.3. Qt is now updated to 5.15.3 KDE Frameworks 5.98.0 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? (In reply to A Linux User from comment #14) > 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? No longer a problem for me. I recently switched from X11 to Wayland and since HDR/10bit display support has landed and I am using a 10bit display, colors are no longer washed out for me. So I am not sure which change "fixed" it for me, either the HDR/10bit support or the switch to Wayland |
Created attachment 140833 [details] base png test file SUMMARY I have a script which converts a png file to another png file and a jpg file. To convert I use imagemagick's convert command. The resulting jpg file is alright but the png file has washed out light colours. The command that I use is this convert test.png -background white -alpha remove test-converted.png The resulting file is properly displayed in firefox, google chrome, GIMP, krita, Okular, Showfoto etc. Only gwenview shows the colour in the image as washed out. My monitor is calibrated and gwenview has perceptual rendering intent and also Apply only embedded colour profile enabled. STEPS TO REPRODUCE 1. Open the attached png file 2. convert it using the imagemagick command mentioned above to another png file 3. then open it in gwenview OBSERVED RESULT Colours are washed out EXPECTED RESULT Colours should appear how they are intended in the image I am also attaching a screenshot showing how it looks on my screen System Information: Operating System: Arch Linux KDE Plasma Version: 5.22.4 KDE Frameworks Version: 5.85.0 Qt Version: 5.15.2 Kernel Version: 5.13.10-arch1-1 (64-bit) Graphics Platform: X11 Processors: 8 × Intel® Core™ i7-4790K CPU @ 4.00GHz Memory: 31.3 GiB of RAM Graphics Processor: NVIDIA GeForce GTX 750 Ti/PCIe/SSE2