Mirror PDFs

  • jano

    jano - 2005-01-08

    I came to Multivalent homepage and installed it in hope, it is able to mirror PDFs as read at comp.text.pdf newsgroup. Would it be difficult to implement mirroring?

    Or can I get a hint how to do it with PDF commands in text file of uncompressed PDF.  Thanks.

    • Tom Phelps

      Tom Phelps - 2005-01-10

      By mirror do you refer to flipping a page's display about a center axis?  You can do it by setting the page's transformation matrix ('cm' PDF command).  You can do this manually with the Uncompress tool, which helpfully labels page content streams with their page number, inserting the cm command with the right parameters at the head of the page stream, then using the Compress tool to make it into a valid PDF again.

    • jano

      jano - 2005-01-10

      Exactly, by mirroring I mean flipping a page about the vertical center axis (as you would see it in the mirror).

      In prepress process I use the mirror printing for small budget project done by offset printing, when instead of producing films by imagesetter you print mirrored pages on transparent papers using laser printer.

      Since my workflow is now purely PDF (using pdftex) it would be nice not going back to Postscript but "mirror" the pages right in the PDF. Unfortunately I have found only commercial tools able to do it easily. And none of them is command-line tool. That's why I posted the suggestion here.

      In Postscript it is done by adding a header at the begining of the document changing the /bophook{} command (I think), but there is no need to do it "manually", there are wrapers, which can do it.

      Anyway, thanks for the hint where to start to study PDF documentation, if nothing reasonable apeers. Or will?


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