Bug 468112

Summary: Use Cairo backend for Poppler wrapper used in Okular
Product: [Applications] okular Reporter: Alexander Wilms <f.alexander.wilms>
Component: PDF backendAssignee: Okular developers <okular-devel>
Status: REPORTED ---    
Severity: normal CC: oliver.sander
Priority: NOR    
Version First Reported In: 22.12.3   
Target Milestone: ---   
Platform: openSUSE   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:
Attachments: PDF which displays rendering artifacts at 150% zoom
Rendering artifacts in Okular at 150% zoom

Description Alexander Wilms 2023-04-03 08:59:44 UTC 
Created attachment 157812 [details]
PDF which displays rendering artifacts at 150% zoom

SUMMARY
Okular displays rendering artifacts when one opens a PDF and zooms in a bit. Apparently this is caused by the Splash backend in Poppler's Qt backend. Enabling the Cairo backend should fix this.


STEPS TO REPRODUCE
1. Download the attachment
2. Open specimen.pdf in Evince and Okular

OBSERVED RESULT
Evince renders the text as expected, all characters are on the same baseline. In Okular, the characters jump up and down.

EXPECTED RESULT
All characters are on the same baseline.

SOFTWARE/OS VERSIONS
Operating System: openSUSE Tumbleweed 20230331
KDE Plasma Version: 5.27.3
KDE Frameworks Version: 5.104.0
Qt Version: 5.15.8
Kernel Version: 6.2.8-1-default (64-bit)
Graphics Platform: X11

ADDITIONAL INFORMATION
https://unix.stackexchange.com/questions/611764/bad-rendering-of-graphics-in-okular-at-higher-zoom-levels
which links to
https://github.com/giddie/poppler-cairo-backend
which links to 
https://bugs.freedesktop.org/show_bug.cgi?id=25240
which links to
https://gitlab.freedesktop.org/poppler/poppler/-/issues/435
which links to
https://gitlab.freedesktop.org/poppler/poppler/-/merge_requests/546
Comment 1 Alexander Wilms 2023-04-03 09:02:07 UTC 
Created attachment 157813 [details]
Rendering artifacts in Okular at 150% zoom