There are artifacts when upscaling a VNC session. STEPS TO REPRODUCE 1. Start a VNC session with krdc. The remote desktop has a resolution of 1920x1080. The screen on which krdc is running has a resolution of 4k. The VNC server can be krfb or tightvnc. 2. Maximize the krdc window and activate the upscaling (button Scale) OBSERVED RESULT Graphical artifacts sometimes appear on the screen. It seams to corresponds to the edges of the part of the image which are refreshed. See the attachment krdc_with_artifacts.jpg. I have made a patch which fixes the problem. See attachment krdc_with_patch.jpg for the result with the patch. The patch is attached and also available at: EXPECTED RESULT No artifacts. SOFTWARE/OS VERSIONS Linux/KDE Plasma: (available in About System) KDE Plasma Version: 5.20.5 KDE Frameworks Version: 5.78.0 Qt Version: 5.15.2 ADDITIONAL INFORMATION
Created attachment 135572 [details] image with artifacts
Created attachment 135573 [details] no artifacts with patch
Created attachment 135574 [details] patch fixing artifacts
Could you please create a Merge Request against https://invent.kde.org/network/krdc ?
A possibly relevant merge request was started @ https://invent.kde.org/network/krdc/-/merge_requests/10
Git commit 0d2fd365b4482b1c167feac09adf0f06f870e347 by Albert Astals Cid, on behalf of Cedric Bregardis. Committed on 13/03/2021 at 17:49. Pushed by aacid into branch 'master'. Fix upscaling artifacts in VncView Edges of updated regions are not correctly painted when upscaling a VNC session. Increasing the updated rectangle by one pixel fixes the problem. M +1 -1 vnc/vncview.cpp https://invent.kde.org/network/krdc/commit/0d2fd365b4482b1c167feac09adf0f06f870e347