Dear Maintainer,

On high DPI monitors (1440p, 4K), where KDE configuration is
set to upscale the interface in System Settings > Hardware >
Display and Monitor > Scale Display > Scale - greater than 1x
(othewise ui elements are too small), gwenview ui seems
correct, but the images it displays are upscaled, making them
blurry/with high pixel blocks (low resolution).

I've uploaded a screenshot to
https://jynus.com/side_by_side.png so you can understand
what I am talking about.

On another application, a-non perfectly crisp image would be
a minor issue, but on an application made explicitly to
visualize images this is a larger issue, impacting its main
functionality (images are shown, but they look bad)-
specially for photography visualization.

To workaround the problem, one can do:

unset QT_SCREEN_SCALE_FACTORS

Before runing gwenview so the upscaling is cancelled for this
application only and the images are shown with an appropiate
resolution.

I belive this to be the same issue as the one tracked
upstream at:

https://bugs.kde.org/show_bug.cgi?id=373178

After changing the graphic card and upgrading the graphic driver, I no
longer have this issue with window scaling. Gwenview and other kde
programs render images correctly. Not sure if the issue was the card
or the driver, or any other kde update, but I no longer have this
issue.