Bug 271673

Summary: Zooming in above 200% causes embeded picture corruption
Product: [Applications] okular Reporter: Māris Nartišs <maris.kde>
Component: generalAssignee: Okular developers <okular-devel>
Status: RESOLVED UPSTREAM    
Severity: minor CC: aacid
Priority: NOR    
Version: 0.12.2   
Target Milestone: ---   
Platform: Gentoo Packages   
OS: Linux   
Latest Commit: Version Fixed In:
Sentry Crash Report:
Attachments: Screenshot displaying corrupted lines
A PDF file for testing
Screenshot displaying corrupted lines
Same PDF rendered with Adobe Reader

Description Māris Nartišs 2011-04-25 09:48:22 UTC
Created attachment 59296 [details]
Screenshot displaying corrupted lines

Version:           0.12.2 (using KDE 4.6.2) 
OS:                Linux

Open a PDF with some drawing (picture). Zoom in more than 200%. Around 212% on stright lines strange rendering artefacts start to appear. Lines are not smooth anymore etc. Increasing zoom-in by single % (213, 214) will make tose corruptions to change locations.

Reproducible: Always
Comment 1 Māris Nartišs 2011-04-25 09:49:26 UTC
Created attachment 59297 [details]
A PDF file for testing

Zoom in to 212% and continue to increase zoom by single %.
Comment 2 Albert Astals Cid 2011-04-26 23:39:17 UTC
Can you please attach a screenshot with some arrow or marker indicating what you see wrong?
Comment 3 Māris Nartišs 2011-04-27 07:34:35 UTC
Created attachment 59350 [details]
Screenshot displaying corrupted lines

A second screenshot. This time problems are marked with small lines. This issue might seem insignificant for such kind of drawing, still one has to keep in mind that PDFs are popular format for map distribution and there such problems are unacceptable.
Comment 4 Christoph Feck 2011-05-04 15:21:58 UTC
Did you verify that in other viewers (non xpdf/poppler based, such as Adobe Reader) the issue is not visible? It could be the math application rendering multiple line segments with rounded coordinates instead of actual curves.
Comment 5 Māris Nartišs 2011-05-05 08:57:38 UTC
Created attachment 59643 [details]
Same PDF rendered with Adobe Reader

Adobe Reader renders same PDF just fine.

Also I was under impression that PNG images are rasters and do not contain vector lines (curves) and thus should not be affected by vector line rendering issues...
Comment 6 Albert Astals Cid 2012-08-09 21:59:32 UTC
We do not render PDF files, if this is a bug (which i doubt) it is a bug in poppler, the library we use for rendering pdf. Please open a bug report in bug tracker at bugs.freedesktop.org