Thanks, Tav, that could indeed be the missing clue. As for adding that to FOP, we'll have to modify the sources for that. I'm not sure if /DeviceRGB is the right value for all cases. Maybe that will actually be cause for a global setting where the user can specify whether he intends to create a CMYK- or RGB-oriented PDF. I'll see if I can make time for a small experiment in the next few days. And of course, I'll have to study the transparency section of the PDF spec in depth at some point.
On 27.09.2009 11:27:42 Tavmjong Bah wrote: > > Hi, > > Jeremias, thanks for your reply. > > I've done a bit more experimenting. Following up on the comment from > the Adobe forum I found a solution to shifting PNG colors with Acroread > at: > > http://bmeps.sourceforge.net/examples.html > > Adding: > > /Group << /S /Transparency /I true /CS /DeviceRGB>> > > to the /Type /Page object for each page gets rid of the color shifts. > > Is there a way I can get Fop to insert this automatically? > > Here are a few additional comments: > > Problem occurs with PNGs, indexed PNGs, JPGs, and less frequently with > SVGs. > > Problem occurs with both Linux and Windows XP Adobe Reader 9.1. The > color shifts are more pronounced on Linux (on Windows one might just > attribute it to an uncalibrated monitor if one didn't compare directly > the corrected, uncorrected PDFs, and original artwork). > > The meanings of the PDF variables can be found starting on page 556 of > the Adobe PDF Reference, Sixth Edition, version 1.7 available at: > > http://www.adobe.com/devnet/pdf/ > > S: Group subtype. > I: Group transparency is isolated. > CS: Group color space. > > That's as far as I got trying to understand the PDF spec. > > Tav > > > On Fri, 2009-09-25 at 18:10 +0200, Jeremias Maerki wrote: > > You've probably hit bug #45809 which we still don't know how to fix. > > > > https://issues.apache.org/bugzilla/show_bug.cgi?id=45809 > > > > On 25.09.2009 15:51:53 Tavmjong Bah wrote: > > > > > > Hi, > > > > > > I am having problems with colors coming out too dark when I insert PNGs > > > (or JPGs) into a PDF document that is then displayed by Acroread on > > > Linux. Evince gets the colors correct. I've searched the web and found > > > these hints: > > > > > > PDF using DeviceCMYK instead of DeviceRGB: > > > http://forums.adobe.com/thread/395247 > > > > > > Converting to index color yields correct color: > > > http://texblog.net/latex-archive/graphics/adobe-reader-wrong-color/ > > > > > > XMLGraphicsCommons Bug 47561: png color profiles seem to get lost... > > > https://issues.apache.org/bugzilla/show_bug.cgi?id=47561 > > > > > > None of these seems to be the exact problem I have. > > > > > > I've prepared two simple PDF files using DocBook and Fop. The first > > > embeds an indexed PNG. This gives the correct color (the un-indexed one > > > gives the wrong color). I then add a second un-indexed PNG that is > > > forced to be on the next page. The indexed PNG on the first page is now > > > displayed too dark. > > > > > > This is all processed with Fop trunk. > > > > > > I've attached the two PDF files, the two PNG's, and the DocBook file. > > > > > > Any help would be greatly appreciated. > > > > > > Tav > > > > > > > > > > > > > > > > Jeremias Maerki > > > > > > --------------------------------------------------------------------- > > To unsubscribe, e-mail: [email protected] > > For additional commands, e-mail: [email protected] > > > > > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: [email protected] > For additional commands, e-mail: [email protected] Jeremias Maerki --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
