LinuxQuestions.org

LinuxQuestions.org (/questions/)
-   Linux - Software (http://www.linuxquestions.org/questions/linux-software-2/)
-   -   cups, pdf and opacity problems (http://www.linuxquestions.org/questions/linux-software-2/cups-pdf-and-opacity-problems-599109/)

BCarey 11-12-2007 01:44 PM

cups, pdf and opacity problems
 
Hi all,

I have a pdf with a semi-opaque watermark. In evince the object is fully opaque. In kpdf the object views semi-transparent but prints fully opaque. In Adobe Reader it prints and views correctly semi-transparent. Printing directly from the command line it prints fully opaque. I think (in my ignorance) it has to do with PostScript Levels ???The problem with Adobe Reader is that I can't print multiple copies!!!.

So, I'd really like to understand what's wrong, but most importantly I'd like to have a cli option to print multiple copies of a bunch of pdfs.

Thanks for any ideas,

Brian

BCarey 11-12-2007 09:01 PM

It seems that only Adobe's pdf-ps filter handles the transparency correctly. Has anyone else had this problem?

Anyway, if anyone else wants to go the command line way, what worked for me was "acroread -toPostScript -landscape *.pdf ps_dir/" which creates PostScript files which I can print with lp, so I can easily automate what I'm doing.

I'd still like to understand why evince and kpdf fail.

Brian

pbille 10-01-2015 11:52 AM

Opaque images - RGB -> RGBA
 
BCarey,

I've seen a similar problem with cups-pdf. A three channel RGB image prints opaque when I print it as PDF. I've had luck converting the three channel RGB to four channel RGBA. The fourth, "alpha" channel is used for opacity.

I use gimp http://www.gimp.org to add an alpha channel to the RGB image. After I add the alpha channel, I save the image as .png or whatever. Subsequently, I use the image in a document and print it with cups-pdf and everything looks fine.

PBille


All times are GMT -5. The time now is 11:26 AM.