Bug 352796 - CMYK modeled PDFs display a color shift
Summary: CMYK modeled PDFs display a color shift
Status: RESOLVED UPSTREAM
Alias: None
Product: okular
Classification: Applications
Component: PDF backend (show other bugs)
Version: 0.23.0
Platform: Arch Linux Linux
: NOR normal
Target Milestone: ---
Assignee: Okular developers
URL: http://oi59.tinypic.com/9k410l.jpg
Keywords:
Depends on:
Blocks:
 
Reported: 2015-09-16 12:15 UTC by Krešimir Čohar
Modified: 2015-09-22 23:05 UTC (History)
1 user (show)

See Also:
Latest Commit:
Version Fixed In:
Sentry Crash Report:


Attachments
an example of the problem using my Histology textbook pdf, in CMYK (2.10 MB, image/png)
2015-09-16 12:17 UTC, Krešimir Čohar
Details
you can use this pdf to test it out (525.82 KB, application/pdf)
2015-09-17 00:36 UTC, Krešimir Čohar
Details

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Description Krešimir Čohar 2015-09-16 12:15:22 UTC
CMYK modeled PDFs display a color shift -- they become slightly more saturated than normal (see included image of Okular vs Google Chrome rendering; Google Chrome renders the colors accurately). The same problem appears in iBooks for iOS.

Reproducible: Always

Steps to Reproduce:
1. Open PDF with CMYK color model. I used my Histology textbook.
2.
3.

Actual Results:  
Everything renders fine except for the colors.

Expected Results:  
Everything should have rendered fine, including the colors. There should be no difference between the colors of a CMYK and RGB color model PDF.
Comment 1 Krešimir Čohar 2015-09-16 12:17:43 UTC
Created attachment 94595 [details]
an example of the problem using my Histology textbook pdf, in CMYK
Comment 2 Albert Astals Cid 2015-09-16 23:02:34 UTC
Need an actual pdf to reproduce (i may also need new eyes since my slight color blindness won't help with this :D but let's worry about that later)
Comment 3 Krešimir Čohar 2015-09-17 00:36:35 UTC
Created attachment 94609 [details]
you can use this pdf to test it out
Comment 4 Albert Astals Cid 2015-09-20 20:50:11 UTC
Could you point me (remember slightly colorblind) in attachment 94595 [details] what is wrong?
Comment 5 Krešimir Čohar 2015-09-21 08:56:36 UTC
there's a shift of blue-violet that's prominently visible in the slides and the lines beneath the slide headings. it would be visible on any color, in any hue/saturation shift.
Comment 6 Albert Astals Cid 2015-09-22 23:03:54 UTC
Now that i realize, sorry but this is not an okular bug, it is a poppler bug.

poppler is the library we use to deal with pdf files, so if the rendering is wrong, it is on their side.

Please report a bug at http://bugs.freedesktop.org/
Comment 7 Krešimir Čohar 2015-09-22 23:05:58 UTC
oh ok will do :D thanks!