Bug 449516

Summary:	Blurry text with X11 for certain zoom levels (and global scaling set to 125%.)
Product:	[Applications] okular	Reporter:	Iyán M. V. <me>
Component:	PDF backend	Assignee:	Okular developers <okular-devel>
Status:	REPORTED ---
Severity:	normal	CC:	aacid, tbertels
Priority:	NOR	Keywords:	X11-only
Version First Reported In:	21.12.1
Target Milestone:	---
Platform:	Other
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:
Attachments:	Not blurry (zoom 100%) Blurry (zoom 125%) Not blurry (zoom 150%) The pdf shown in the screenshots

Description Iyán M. V. 2022-02-02 19:17:16 UTC

SUMMARY
Some PDFs (cannot replicate for all) get blurry for certain levels of zoom, but only when going from less to more zoom.

STEPS TO REPRODUCE
1. Open PDF
2. Zoom in (sometimes 125% is blurry, sometimes 150%)
3. Zoom out (is not blurry anymore)
4. (When a zoom level is found that makes PDF blurry) Zoom one more level (not blurry), and zoom out again (now not blurry).

SOFTWARE/OS VERSIONS
Operating System: Arch Linux
KDE Plasma Version: 5.23.90
KDE Frameworks Version: 5.90.0
Qt Version: 5.15.2
Kernel Version: 5.16.4-arch1-1 (64-bit)
Graphics Platform: X11
Processors: 8 × 11th Gen Intel® Core™ i5-1135G7 @ 2.40GHz
Memory: 15.4 GiB of RAM
Graphics Processor: Mesa Intel® Xe Graphics

ADDITIONAL INFORMATION
This can also be observed in the integrated PDF viewer (preview) of Kile, for example.
I'm using a global scale of 125%.
If you cannot find a PDF where you can reproduce this behavior, I can share one where I observe this on two different devices.

Comment 1 Albert Astals Cid 2022-02-02 19:40:28 UTC

Please attach the PDF and a screenshot of what you think it's blurred.

Also are you running some hidpi screen and not 1:1 scaling?

Comment 2 Iyán M. V. 2022-02-02 21:35:09 UTC

Created attachment 146194 [details]
Not blurry (zoom 100%)

Comment 3 Iyán M. V. 2022-02-02 21:36:22 UTC

Created attachment 146195 [details]
Blurry (zoom 125%)

Comment 4 Iyán M. V. 2022-02-02 21:36:51 UTC

Created attachment 146196 [details]
Not blurry (zoom 150%)

Comment 5 Iyán M. V. 2022-02-02 21:37:45 UTC

Created attachment 146197 [details]
The pdf shown in the screenshots

Comment 6 Iyán M. V. 2022-02-02 21:38:47 UTC

(In reply to Albert Astals Cid from comment #1)
> Please attach the PDF and a screenshot of what you think it's blurred.

Done.

> Also are you running some hidpi screen and not 1:1 scaling?

1440p on my desktop and 1080p on the laptop, both with global scaling set to 125%.

Comment 7 Albert Astals Cid 2022-02-02 22:23:43 UTC

Can you try with global scaling at 100% and see if you can reproduce the problem?

Comment 8 Iyán M. V. 2022-02-02 22:33:22 UTC

With global scaling at 100% it's never blurry.

Comment 9 Iyán M. V. 2022-02-02 23:00:01 UTC

Also, just with X11. In Wayland it doesn't happen even with the global scaling at 125%.

Comment 10 TraceyC 2025-02-24 17:58:17 UTC

Adding the x11-only keyword