I can only zoom thumbnails to 256x256 pixels. I would like to have bigger thumbnails on ThinkPad T520 15 inch Full HD display (1920x1080) as 256x256 is too small to preview image nicely for sorting them into folders. Reproducible: Always Steps to Reproduce: 1. Raise zoom slider to maximum Actual Results: 256x256 preview size maximum Expected Results: Larger previews :)
Thumbnails currently use the xdg thumbnails standard, which only supports 128 and 256 pixel sizes.
This is another "High-dpi issue". On 4k monitor thumbnails size is really too small to see even if set 256px.
The 256px thumbnails should scale appropriately if you're using HiDPI. Still it would be nice to see even larger thumbnails once the XDG spec supports it.
A possibly relevant merge request was started @ https://invent.kde.org/network/kio-extras/-/merge_requests/62
Git commit 87f12f936e053708ace0adc8b2bd8fc1c9bd38a2 by Méven Car. Committed on 10/07/2021 at 04:11. Pushed by meven into branch 'master'. Thumbnails: Make thumbnail generation devicePixelRatio aware Use the metadata devicePixelRatio to scale up dimensions of thumbnails generated. Sets the devicePixelRatio on the output QPixmap according to the thumbnail generated. Make the Text Thumbnail creator devicePixelRatio aware. Follows xdg thumbnail specs 0.9 https://specifications.freedesktop.org/thumbnail-spec/thumbnail-spec-latest.html FIXED-IN: 21.08 M +14 -13 thumbnail/textcreator.cpp M +3 -3 thumbnail/textcreator.h M +1 -0 thumbnail/textthumbnail.desktop M +3 -0 thumbnail/thumbcreator.desktop M +87 -35 thumbnail/thumbnail.cpp M +3 -1 thumbnail/thumbnail.h https://invent.kde.org/network/kio-extras/commit/87f12f936e053708ace0adc8b2bd8fc1c9bd38a2