Bug 502242

Summary:	Uneven preview sharpness!!
Product:	[Applications] digikam	Reporter:	_ <myaccount132>
Component:	Preview-Image	Assignee:	Digikam Developers <digikam-bugs-null>
Status:	RESOLVED NOT A BUG
Severity:	normal	CC:	metzpinguin
Priority:	NOR
Version First Reported In:	8.6.0
Target Milestone:	---
Platform:	Other
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:	8.7.0
Sentry Crash Report:
Attachments:	Image previewed is normally sharp. Image previewed is abnormally unsharp.

Description _ 2025-03-31 13:59:22 UTC

Previewing (F3) images makes them randomly sharp or unsharp. I'm attaching two image screenshots from same series which show the difference. When I open them in gimp, they're same quality.

I've often discarded and deleted unsharp pictures based on review so this causes data loss. I've noticed this in earlier versions too, and already did deleted files for this set too, but remembered to check again this time and was still able to restore them.

Preview should show sharpness consistently to be reliable to assess picture quality without opening them in editor.

Comment 1 _ 2025-03-31 13:59:42 UTC

Created attachment 179884 [details]
Image previewed is normally sharp.

Comment 2 _ 2025-03-31 14:00:00 UTC

Created attachment 179885 [details]
Image previewed is abnormally unsharp.

Comment 3 _ 2025-03-31 14:10:32 UTC

Addition: this possibly requires images to be even slightly zoomed in. 

I went on shuffling images in and out between editor and preview and view ended up messing sharpness also from the sharp example attached, but ui still retained sharpness in other.

Comment 4 Maik Qualmann 2025-03-31 16:25:51 UTC

For speed reasons, the preview from the embedded preview image is enabled by default. Depending on the camera, this can be a low- to very low-resolution image. Enable full automatic preview of the image in the digiKam settings under View. It is also possible to disable anti-aliasing when zooming.

https://docs.digikam.org/en/setup_application/views_settings.html#preview-settings

Maik