Bug 692415 - Too many gray lines
Summary: Too many gray lines
Status: RESOLVED DUPLICATE of bug 691930
Alias: None
Product: MuPDF
Classification: Unclassified
Component: mupdf (show other bugs)
Version: unspecified
Hardware: PC All
: P4 normal
Assignee: Tor Andersson
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2011-08-09 23:02 UTC by Pedro Rivera
Modified: 2011-08-29 19:52 UTC (History)
0 users

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Too many gray lines (104.68 KB, application/pdf)
2011-08-09 23:02 UTC, Pedro Rivera 		Details
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Description Pedro Rivera 2011-08-09 23:02:43 UTC 
Created attachment 7762 [details]
Too many gray lines

The attatched PDF when displayed renders many gray lines. These lines do not show up in Acrobat reader.

When I change the anti-alias level to 0 less lines are displayed, but when set to 8 an excessive amount of gray lines appear.

Side note: These gray lines do not appear is SumatraPDF 1.7.

Thanks,

Pedro
Comment 1 Pedro Rivera 2011-08-19 04:01:27 UTC 
After further testing I realized that these "grey" lines only appear when I don't set the the background color of the pixmap.

If I do 
   fz_clear_pixmap_with_color(pix, 255);
then no lines and pages look perfect.

If I do
  fz_clear_pixmap(pix);
in order to preserve alpha I get the "grey lines"

P+
Comment 2 Tor Andersson 2011-08-29 19:52:52 UTC 
That's anti-aliasing at work. Turn off "Enhance thin lines" in Adobe Reader and you also get gray lines. Rendering with a transparent background makes these problems more visible. They're still there with a white background, just less obvious.

*** This bug has been marked as a duplicate of bug 691930 ***