Bug 408455 - Preview of files inside a folder looks fuzzy when fractional display scaling is used
Summary: Preview of files inside a folder looks fuzzy when fractional display scaling ...
Status: RESOLVED DUPLICATE of bug 390488
Alias: None
Product: kio-extras
Classification: Frameworks and Libraries
Component: Thumbnails and previews (show other bugs)
Version: unspecified
Platform: Arch Linux Linux
: NOR normal
Target Milestone: ---
Assignee: Plasma Bugs List
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2019-06-08 14:30 UTC by Patrick Silva
Modified: 2020-05-04 19:17 UTC (History)
2 users (show)

See Also:
Latest Commit:
Version Fixed In:

Attachments
screenshot (83.70 KB, image/png)
2019-06-08 14:30 UTC, Patrick Silva 		Details
screenshot of scale factor 2 (451.95 KB, image/png)
2019-06-11 21:54 UTC, Patrick Silva 		Details
2x scaling, largest size icons (164.89 KB, image/png)
2019-06-11 22:23 UTC, Nate Graham 		Details
Screenshot of the right panel's preview of an PDF with scaling 1.5 (91.72 KB, image/png)
2020-05-04 17:58 UTC, postix 		Details
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Description Patrick Silva 2019-06-08 14:30:01 UTC 
Created attachment 120694 [details]
screenshot

STEPS TO REPRODUCE
1. open system settings > display and monitor > click "Scale display" button and set display scale factor to 1.2 
2. relogin 
3. open dolphin and observe the preview of folders containing pictures/videos

OBSERVED RESULT
as we can see in the attached screenshot, the preview of the files inside a folder looks fuzzy

EXPECTED RESULT
crisp previews

SOFTWARE/OS VERSIONS
Operating System: Arch Linux 
KDE Plasma Version: 5.15.90
KDE Frameworks Version: 5.59.0
Qt Version: 5.13.0 RC
Comment 1 Nate Graham 2019-06-10 20:26:05 UTC 
Works okay with integer scaling though?
Comment 2 Patrick Silva 2019-06-11 11:25:01 UTC 
This bug does not occur with scale factor 1. I can't test scale factor 2 because my display is 1080p.
This bug only occurs with scale factor 1.2 when I set the icon size to 128px.
Comment 3 Nate Graham 2019-06-11 13:18:11 UTC 
You can still use 2x scaling with your 1080p screen; things will just be small. :)

Alternatively you can do it only for Dolphin by running `QT_SCALE_FACTOR=2 dolphin`
Comment 4 Patrick Silva 2019-06-11 21:54:06 UTC 
Created attachment 120803 [details]
screenshot of scale factor 2

With scale factor 2 sometimes the previews are fuzzy, sometimes they are blurry, sometimes they look fine. It depends on the icons size.
Comment 5 Nate Graham 2019-06-11 22:23:13 UTC 
Can reproduce. They should be much sharper than they are.
Comment 6 Nate Graham 2019-06-11 22:23:49 UTC 
Created attachment 120805 [details]
2x scaling, largest size icons
Comment 7 postix 2020-05-04 17:58:31 UTC 
Created attachment 128145 [details]
Screenshot of the right panel's preview of an PDF with scaling 1.5

It's not only the previews of files inside folders, but also the preview in the right details panel, when using scaling 1.5. 

(I guess this is related? Otherwise I may open another report.)
Comment 8 Patrick Silva 2020-05-04 18:19:11 UTC 
Already reported as bug 390488
Comment 9 Nate Graham 2020-05-04 19:17:33 UTC 
Oops, thanks!

*** This bug has been marked as a duplicate of bug 390488 ***