Created attachment 167659 [details] Annotated Screenshots Explaing Poor Quality of Backgrounds SUMMARY *** "Next" Backgrounds of KDE 6 are very poor quality. *** STEPS TO REPRODUCE 1. Copy the content of "/usr/share/wallpapers/Next/contents/" to your "/home/user/Pictures"; 2. Take a closer look at the 5120x2880 PNG (downsacled PNGs have even worse quality). OBSERVED RESULT 1. Ugly banding around the tree and sky around the sun (see annotated screenshot); 2. Complete lack of aliasing (see screenshot); 3. Leftovers from JPG compression reveal that PNG was made from a JPG (see screenshot); 4. Info about 5120x2880 file reveals its just only 8-bit depth; 5. Due to linear downscaling, lower resolution PNGs have worse quality. EXPECTED RESULT 1. Provide high quality original 5120x2880 PNG; 2. Provide genuine 16-bit depth of the original PNG; 3. Provide genuine PNG, that isn't converted from JPG; 4. For lower resolutions, downscale the new 5120x2880 HQ-16-bit PNG, using lanczos function with four lobes. SOFTWARE/OS VERSIONS KDE Plasma Version: 6.0.2 KDE Frameworks Version: 6.0.0 Qt Version: 6.6.2 Graphics Platform: X11 Graphics Processor: Intel HD ADDITIONAL INFORMATION $ sudo pacman -Syyu && sudo pacman -S imagemagick inkscape gimp --noconfirm a) use graphics vectoring to draw round objects without aliasing; b) do not use jpg, its a lossy compression, leaving ugly artifacts; c) when exporting graphic vectors to PNG in GiMP, use wavelet antialiasing, before final exporting to PNG.
I can confirm the visual issues now that you've pointed them out. I can also confirm that they're essentially un-noticeable in normal usage unless I'm zooming in at like 1000% to specifically hunt for visual artifacts. That makes it a practical non-issue for 99.9999% of people. What's going on here is that ultimately the quality level of the wallpapers we get is bounded by our decision to solicit art from the community, rather than hiring a professional graphic artist to make us nice SVGs-based art that can be processed perfectly to yield perfectly size-optimized 16-bit PNGs every single time. Sometimes we're lucky enough to get that anyway, sometimes we aren't. It sounds like you know a lot about image optimization and lossless art pipelines. Maybe you'd like to get involved to help us out? See https://community.kde.org/Get_Involved/design if this tickles your fancy!