PNG and SVG thumbnails on Dolphin blurred. Please see screens with compare Nautilus(left)/Dolphin(right): http://imgur.com/a/ExRCx Manajro x86_64 KDE 5.6.4 Dolphin 16.04.1 Reproducible: Always
It took me a while to see what you mean, so here are some steps to see the problem: - Start KMag, point it at the screenshot. - Compare accessories-notes.svg. - Note how Dolphin renders the SVG in such a way that antialiasing on the inner horizontal lines as well as the yellow outline occurs, while in Nautilus the SVG is rendered snapped to the pixel grid, so no antialiasing occurs as probably intended by the icon designer. Testing with Qt 5.10.0, KF 5.40, Dolphin 17.08.3, the problem is still there. Maybe the problem is caused by Dolphin rendering a different size than the icon is optimized for, e.g. when previewing /usr/share/icons/breeze/apps/64/ with the thumbnail size set to 64px, the blur still occurs. I see no PNGs in Dolphin in the screenshot, therefore changing the title of the bug for now to only focus on the SVG rendering problem. Also, Nautilus skips the shadow/frame for SVGs (just like Gwenview) which makes sense, there is Bug 258514 for changing that in Dolphin.
I'm designer and draw icons (also i'm developer Breeze icon theme too), gui interface and etc. Often need check pixel align and i can't doing this. I need install nautilus or other FM, because Dolphin have frame for all preview thumbnails and thumbnails blurred. All other FM's not have this frame and i can check pixel align - PCManFM-QT, Nautilus, Pantheon Files, Thunar and etc... It's bug only on Dolphin. It's very uncomphortable for development. See again on new screenshot: - On left Dolphin on right Nautilus - Original icon size 48px - All icons have pixel align initially - Nautilus show prefect pixel align - Dolphin have frame, therefore icons reduced and blurred (it's good looking on unturned.svg - eyes blurred) I can't check my work on dolphin, because it's impossible. I must instal another FM and use it.
Created attachment 109788 [details] see on fullscreen
Frame thumbnail on Dolphin have size 48px but icon preview really reduced - it's blurred all elements on icon
I think need disable or remo this frame thumbnail. It's really not needed and spoil/change original image on preview.
it's happened not for SVG only. PNG's and other images blurred too, because frame/shadow used for that.
Also frame have wrong area size - it's 40px (without shadow). I think it's need check for other sizes too. Maybe it's help you.
Created attachment 109790 [details] zoom 48px thumbnail
Thanks for your additional comments. I suspect the blurs for SVG and PNG are a bit different each, caused by the icon shown too small (smaller area to render the SVG in vs. smaller area to downscale a prerendered PNG to), but nevertheless I adapted the bug title slightly. This should be solved in two steps: Remove the shadow in Bug 258514, after that check whether any additional steps are necessary for your bug. FWIW, Gwenview does not have shadows, but probably won't be good enough for you either due to lack of a precise thumbnail size control.
Any news? I can't worked on Dolphin, i can't check pixel align - all previews rendered with preview mask (with border and shadow). Why? Other apps not have yet. See example PCManFM-Qt (Qt5), Krusader (Qt5) or NautiLus (GTK3). All file managers rendered original image without mask, borders, shadows and etc... Why you don't want fix that?????????????
Created attachment 114741 [details] compare
*** Bug 415334 has been marked as a duplicate of this bug. ***