OS: Fedora 42 with KDE on Wayland
I've found 2 problems with fractional scaling under Linux/Wayland on both KDE and Gnome (same behavior).
"Scale on HiDPI screen: 1 image pixel equals 1 screen pixel" is checked.
First problem:
View->Auto zoom = "Fit image to desktop" stops setting correct image size as soon as I set scaling other than 100%.
On 100%scale.jpg you can see no problem with initial startup image size. The size is also what Gwenview shows as 100%.
- 100%scale.jpg (435.61 KiB) Viewed 25 times
- 125%scale startup.jpg (552 KiB) Viewed 25 times
Even if I ignore initial image size and resize the image manually to see 100% the size is not the same as in Gwenview.
125%scale 100zoom.jpg shows how 100% zoom looks like in XnView vs 100% zoom in Gwenview.
- 125%scale 100zoom.jpg (604.36 KiB) Viewed 25 times