Hi John,
There are a few ways to do this. Option 1 is one of the many online PDF file size reducer tools. They work to a certain extent, but I've never had that much success with them.
Option 2 (the 'proper' way) is to extract all the images from the PDF container, reduce the size of these files and then wrap them into a new PDF file.
To extract, you can use the full version of Adobe Acrobat or Photoshop, but there are also plenty of freeware / open source alternatives
e.g. For Linux: http://linuxcommand.org/man_pages/pdfimages1.html
or a port of xPDF for Windows: http://www.foolabs.com/xpdf/download.html
(there are plenty of others out there)
To reduce the size of images, Irfanview (Windows)is hard to beat: http://www.irfanview.com/
I would suggest converting the bitmaps to JPEG or PNG. Irfanview has a useful batch processing tool.
imagemagick on Linux can also do this task very effectively. There is also a Windows port available
To create the final PDF, you could use the full version of Adobe Acrobat, imagemagick (Linux or Windows port) or any number of free Windows / online tools.
http://stackoverflow.com/questions/8955425/how-can-i-convert-a-series-of-images-to-a-pdf-from-the-command-line-on-linux
Many thanks,
Tim
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Faculty IT Manager, IT
University of Leeds
-----Original Message-----
From: Research Data Management discussion list [mailto:[log in to unmask]] On Behalf Of John Milner
Sent: 08 July 2015 09:00
To: [log in to unmask]
Subject: Converting overlarge PDF scans
I have a large number of historic papers that appear to have been scanned as
bitmaps and then presented as PDFs. The result is files that are around 30mb
and upwards to 100mb in some cases. Does anyone know if there is any way
these can be reduced in size?
John K. Milner
Mail to: [log in to unmask]
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