Created attachment 121921 [details]
Screenshot of icons on the desktop with poor rendering

SUMMARY
Icons rendered on the desktop show poor anti aliasing (in other words: edges that border transparent pixels are jagged) This is seen at all icon sizes; tiny, small, huge, etc..  However, icons seen throughout the rest of the KDE plasma GUI (for example icons viewed in Dolphin File Manager), render with clean, anti-aliased edges.  

One quirk, image files that live on the desktop (.png, .svg. etc) render cleanly.  See attached image, "KDE_Desktop_Icon_Rendering_Poor_Aliasing.png"  In this screen grab you'll note that the file named "drawing.svg" renders a clean edged preview while the other two icons do not (one of these badly rendered icons belongs to a folder named "TEST" which is, actually, using the "drawing.svg" image as its icon).



STEPS TO REPRODUCE
1. Create a folder, application, document, or link with an icon on the desktop


OBSERVED RESULT
Poor icon rendering (possibly scaling issue?) resulting in aliased, jagged edges around the edges of the icons.

EXPECTED RESULT
Clean icon rendering with anti-aliased edges that is consistent with the rest of the KDE Plasma environment

SOFTWARE/OS VERSIONS

Linux/KDE Plasma: Kubuntu 18.04
(available in About System)
KDE Plasma Version: 5.12.8
KDE Frameworks Version: 5.44.0
Qt Version: 5.9.5

ADDITIONAL INFORMATION