Bug 689991 - tiffsep device with Multithreading produces invalid results
Summary: tiffsep device with Multithreading produces invalid results
Status: RESOLVED WORKSFORME
Alias: None
Product: Ghostscript
Classification: Unclassified
Component: General (show other bugs)
Version: 8.63
Hardware: PC Windows XP
: P4 normal
Assignee: Ray Johnston
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2008-08-04 04:57 UTC by Nikolai Tasev
Modified: 2011-12-09 07:23 UTC (History)
0 users

See Also:
Customer:
Word Size: ---


Attachments
TestSample (1.84 MB, application/pdf)
2008-08-04 05:00 UTC, Nikolai Tasev
Details
SimpleTiffSepTest.pdf (16.46 KB, application/pdf)
2008-09-17 15:44 UTC, Adam Augusta
Details
sep.s0.tif (40.82 KB, application/tiff)
2008-09-17 15:47 UTC, Adam Augusta
Details

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Description Nikolai Tasev 2008-08-04 04:57:18 UTC
I am using a double core Pentium processor and set the 
NumRenderingThreads = 2

When I run the tiffsep device to generate the color separations
I get invalid results. For some color I get all black, for some all white,
and for some only part of the objects in the PDF.

This happens on several files with more complex structure,
images with spot color on top, images with transparency.
Comment 1 Nikolai Tasev 2008-08-04 05:00:44 UTC
Created attachment 4254 [details]
TestSample

On this test sample tiffsep fails with
Multithreading.
Comment 2 Adam Augusta 2008-09-17 15:44:34 UTC
Created attachment 4404 [details]
SimpleTiffSepTest.pdf
Comment 3 Adam Augusta 2008-09-17 15:47:12 UTC
Created attachment 4405 [details]
sep.s0.tif

Created using:
gswin32c -sDEVICE=tiffsep -dBATCH -dNOPAUSE -dTextAlphaBits=4
-dGraphicsAlphaBits=4 -r144 -sOutputFile=sep.tif SimpleTiffSepTest.pdf

Ghostscript v8.63
Comment 4 Ray Johnston 2011-12-09 05:00:00 UTC
This works for me with 904. Since this was reported some time ago and was
against 8.63, it undoubtedly has been fixed. Note that the bug report was
sort of suspect since it mentions 'multithread', but the command line given
in comment #3 didn't specify -dNumRenderingThreads=2.
Comment 5 Nikolai Tasev 2011-12-09 07:23:32 UTC
(In reply to comment #4)
> This works for me with 904. Since this was reported some time ago and was
> against 8.63, it undoubtedly has been fixed. Note that the bug report was
> sort of suspect since it mentions 'multithread', but the command line given
> in comment #3 didn't specify -dNumRenderingThreads=2.

I have missed to specify the NumRenderingThreads as I copied my default usage flags. But the problem was indeed happening on multithreaded usage. 

Since this and other problems with PDFs with transparency I have stopped using Ghostscript. If I gather some time will check again rendering results.