Preview Pictures of photos in lighttable mode are blurry
When viewing photos in lighttable mode I noticed that the preview pictures are displayed much more soften than the photos really are. This happens on all zoom levels.
This problem is most noticeably on photos, which got rotated in darktable mode.
#1 Updated by Anton Keks over 5 years ago
It was blurry before, but after today's update from unstable PPA it got even worse. Now all photos looks like they are out of focus in Lighttable mode, but they instantly get sharp after entering Darkroom mode.
Today I received this version: 1:1.0+1632~g684370a-0pmjdebruijn1~precise
It seems that it was better with previous builds, like 1:1.0+1545~g84773bf-0pmjdebruijn1~precise
#2 Updated by Tobias Ellinghaus over 5 years ago
- Status changed from New to Incomplete
- Priority changed from High to Medium
- % Done changed from 0 to 20
- Category changed from General to Lighttable
- Affected Version set to git development version
Please check both the maximum size in the preferences (this used to determine the thumbnail size, too, right?) and if you are using embedded previews. I never saw anything like that.
#3 Updated by Ivan Korotkov over 5 years ago
I can confirm this with latest darktable from git (updated Oct 2). Max preview size set to 2400x1400.
Embedded previews are displayed sharp, but previews of processed images (or all images when 'use half-size raw' is selected) are blurred.
My best guess is that this happens due to insufficiently large mipmap level being selected by |dt_mipmap_cache_get_matching_size| (it looks like it tries to find nearest size, not nearest greater or equal size).
#4 Updated by Johannes Hanika over 5 years ago
can you try to set your preview size to something reasonable (a little smaller than screen resolution)? there's a slight chance you pay to compute that oversized thumb and then we use cairos blurriest resampling mode to bring it back to your screen size.
of course also check the interpolation mode in your preferences.
#5 Updated by Anton Keks over 5 years ago
Johannes, I think you are right. After connecting a bigger monitor, the thumbs now look decently sharp, but making darktable window smaller blurs the image again considerably.
The interpolator is set to lanczos3, but it seems to be irrelevant here.
Today on IRC houz also mentioned that this might be a scaling issue. Would be great to fix it!