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Outputs: Reducing PDF file size? - Visokio Forums
Outputs: Reducing PDF file size?
  • Alexander     Alexander March 26, 2013 5:30AM

    We are using the PDF batch output on a daily basis. The PDF files that we generate are rather large. (Up to 30 MB)
    As we aim to email these files, we are encountering problems with the maximum size of attachments.

    What can we do to reduce the size of the files? I have the image quality already reasonably low (value=2).

    Hope you guys can help.

    Regards Alexander
  •     michael March 26, 2013 6:26AM
    Hi Alexander,

    To compress PDF files you can use "Post-process command" option and third party applications such as

    See this post:
  •     chris March 26, 2013 6:38AM
    You can specify this in the "Post process command" column in the batch configuration file.
  • Alexander     Alexander March 26, 2013 6:39AM
    I'll have a look! Thanks for the rapid response.
  • Alexander     Alexander April 24, 2013 11:17AM
    Dear Chris and Michael,

    From which version/build is this available. In 2,7 b 480 I cannot find this column.
  •     chris April 24, 2013 11:44AM

    This is in Omniscope 2.8. I'm not sure exactly what version it was put in, but if you download the latest version (b790) you should see this functionality.


  • Alexander     Alexander April 24, 2013 1:59PM

    That is bad news. We are having trouble exporting to PDF in a reasonable file size.
    Now we have PDF's that contain 4 tabs of omniscope and are almost 8 GB. We cannot mail such big files. And we want to export up to 20 pages.

    Do we have other options in 2.7 to limit the file size?

    Hope you can help.
  •     chris April 25, 2013 5:33AM

    I'm assuming you mean the PDF files are 8MB and not 8GB.

    In Omniscope 2.7 there is an "Image quality" slider in the PDF publisher block. If you reduce the image quality you will also reduce the size of the file. In the batch publisher you can configure this in the "JPEG image quality" column.

    You could also reduce the size of the window, which will in turn reduce the size of the PDF screenshot.

    Finally, Omniscope 2.8 will shortly become the stable release. Will you be able to upgrade when this happens? If not, can you let us know precisely why not.


  • Alexander     Alexander April 25, 2013 5:54AM
    Correct! I meant 8MB. The quality and window size are already as low as possible for this purpose.

    As soon as 2.8 is stable we will upgrade. The hesitations are now only based on the blocks that are not backwards compatible. Are there any other users that have hesitations?

    I know that you cannot make any promises about release dates, but are we talking about weeks or months?

  •     michael April 25, 2013 6:15AM
    You can use third party software to optimise it, see
    See also this post: for how to optimise PDF in Omniscope 2.8.

    In Omniscope 2.7:

    - If you need to compress a single PDF file you can use Ghostscript directly.

    - If you export lots of PDF files in some directory and you want to compress all of them automatically, you can write a batch command file that goes through all those PDF files, optimises them and writes optimised version to another file.
    You can start this batch file manually or somehow automate it.. after you generate raw PDFs...

    For example you can do something like this:
    1) Install;
    2) Download optimise_pdf.txt and batch_opt_pdf.txt and change the file extension to .bat;
    2) put batch_opt_pdf.bat and optimise_pdf.bat to the folder with not optimised PDFs;
    3) run batch_opt_pdf.bat from command line, you'll see that the batch file will run Ghostscript (white window). It can take quite long time to run it depending on the file sizes;
    4) in the same folder you'll find optimised files "optimised_.....pdf".

    Please double check batch file script, make sure that you understand how it works:


    forfiles /m *.pdf /c "cmd /c optimise_pdf.bat @file "


    set FILE_NAME=%~1
    echo %FILE_NAME%
    echo optimised_%FILE_NAME%
    "C:\Program Files\gs\gs9.05\bin\gswin64.exe" -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -dPDFSETTINGS=/ebook -dNOPAUSE -dQUIET -dBATCH -sOutputFile="optimised_%FILE_NAME%" "%FILE_NAME%"
  • Alexander     Alexander April 25, 2013 7:12AM

    Thanks a lot! Hope I can get this working.
    As I see it, this would be a good workaround until we upgrade to 2.8.


  • Alexander     Alexander May 1, 2013 6:20AM

    I got it working. Works great!!

    Also the different levels quality that GS offers is helping us for different purposes.
  • Alexander     Alexander August 6, 2013 7:59AM

    I have an additional question regarding the discussion above. I would like the scheduler to execute the batch_opt_pdf.txt. But when I execute this .bat with the command in the scheduler, no files are found. When I execute the .bat all the pdf's are processed.

    Any ideas?
  •     michael August 7, 2013 6:52AM
    Can you make sure that you are using absolute paths everywhere, e.g. C:/.... or you changing the directory in your .bat file before all other commands, e.g.:

    cd "C:/folder_with_pdf_files"

    Because if you are using relative paths then the current path is not where .bat file is but where it is called from. So for example for the scheduler the current folder will be
    Something like "C:\Users\.....\AppData\Local\Visokio Omniscope app\" and all commands with relative paths will search for files relative to this folder.
  • Alexander     Alexander August 7, 2013 12:14PM
  • syedabbas548 February 16, 2016 2:28AM
    Hi Michael,

    Thanks for the post. It really helped me. But I have a little Hiccup I want the output files to be saved in different directory. Is it possible. If yes, Please let me know how can i achieve this.

    Thanks in advance.
  •     chris February 16, 2016 5:42AM

    I've sent you a private message.


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