Bugs item #723, was opened at 2007-01-25 07:27 You can respond by visiting: http://sarovar.org/tracker/?func=detail&atid=493&aid=723&group_id=106 Category: Image inclusion Group: v1.40.1

Status: Closed Resolution: Works For Me Priority: 5 Submitted By: Mark Henning (markhe) Assigned to: Martin Schröder (oneiros) Summary: Pale colors when using transparency in PNG graphics

Initial Comment: Hi@all! I hope this is the right place to report this problem: If there is any transparency definition in a PNG file (e.g. transparency by a certain color or given by a mask), then all graphics on the page show pale colors. Graphics on pages before or after this page show normal colors. This is confirmed in several versions of Adobe Acrobat Reader. Ghostview/Ghostscript does not show this behaviour. The reason for this viewer-dependency might be a missing transparency-definition in the PDF file which makes it ambiguous, as reported by Andreas Lobinger in de.comp.text.tex; thread "Blasse Farben bei transparentem PNG in pdftex". ----------------------------------------------------------------------

Comment By: Martin Schröder (oneiros) Date: 2007-01-26 12:12

Message: Logged In: YES user_id=421 Since this only shows up in AR and two high-end RIPs don't have any problems, this seems to be an AR problem. ---------------------------------------------------------------------- Comment By: Mark Henning (markhe) Date: 2007-01-26 07:07 Message: Logged In: YES user_id=4174 O.K., there are readers showing the problem and readers not showing the prob. There are two possibilities for that: a) The generated PDF is O.K. and there is a bug in the Adobe Reader. b) The generated PDF is ambiguous (as mentioned by Andres Lobinger; I previously told) and it depends on "internal defaults" of the reader whether the bug shows up or not. Finally, the answer can only be found within the generated PDF and a comparison with the PDF specs. Unfortunately, I have absolutely no idea about the internals of PDF. In the usenet post from Andreas Lobinger he told how he looked into the PDF (maybe this helps): Basis: http://sourceforge.net/projects/pdfplayground/ Script: #!/usr/bin/env python import sys sys.path.append("/homes/lobingera/Sources/PostPdf/ pdf031205") import pdftool import pdfo x,t,r = pdftool.pfile(sys.argv[1]) print "trailer" print pdftool.printall(t) for a in x.allused(): n1 = pdfo.pdfo(a,x.getgen(a)) n1.content,n1.stream = pdftool.pxobj(r,x,a) print n1.show('toscreen') ---------------------------------------------------------------------- Comment By: Martin Schröder (oneiros) Date: 2007-01-25 18:05 Message: Logged In: YES user_id=421 Attached the results of rendering this with two professional RIPs (Jaws and Harlequin). I don't see it there... ---------------------------------------------------------------------- Comment By: Martin Schröder (oneiros) Date: 2007-01-25 16:15 Message: Logged In: YES user_id=421 Ah, now I see it. Inded, AR7.0.9 shows a difference. The problem also shows with files generated by pdftex 1.40.1 ---------------------------------------------------------------------- Comment By: Mark Henning (markhe) Date: 2007-01-25 16:08 Message: Logged In: YES user_id=4174 Sorry; I forgot to check the checkbox for uploading the file. ---------------------------------------------------------------------- Comment By: Mark Henning (markhe) Date: 2007-01-25 16:06 Message: Logged In: YES user_id=4174 I rechecked with Adobe Acrobat 7.0 and Adobe Acrobat 7.0.9 on Win2000 SP4, both showed the color differences (see the PNG file I uploaded. It shows a direct comparison.). If you checked the PDF and say that it is O.K., then there must be a bug in Adobe Reader. I will contact Adobe then. ---------------------------------------------------------------------- Comment By: Martin Schröder (oneiros) Date: 2007-01-25 14:53 Message: Logged In: YES user_id=421 I see no problems with AR 7.0.9, kpdf 0.5.1 and gs 8.54 on SUSE 10.1. ---------------------------------------------------------------------- Comment By: Martin Schröder (oneiros) Date: 2007-01-25 14:51 Message: Logged In: YES user_id=421 Pointer to the threat on dctt: http://groups.google.de/group/de.comp.text.tex/browse_thread/thread/758dcc47... An example: http://www.homolog.de/temp/PNGTransparencyBug.zip ---------------------------------------------------------------------- You can respond by visiting: http://sarovar.org/tracker/?func=detail&atid=493&aid=723&group_id=106