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Check image compression used in PDF document?


Question

Is it possible to find out what compression algorithms have been used for images in a PDF document?

2012/09/02
1
7
9/2/2012 11:43:00 PM

You can use pdfimages -list $file on Unix/Linux systems, on Windows maybe you can install poppler to get access to the tool (see https://en.wikipedia.org/wiki/Pdfimages). Note that this is a command line application, without graphical user interface. Its output will look like

page   num  type   width height color comp bpc  enc interp  object ID x-ppi y-ppi size ratio
--------------------------------------------------------------------------------------------
   1     0 image    1240  1753  gray    1   8  image  no         8  0   150   150  301K  14%
   2     1 image    1240  1753  gray    1   8  image  no        22  0   150   150  281K  13%
   3     2 image    1240  1753  gray    1   8  image  no        36  0   150   150  336K  16%

Where the enc column tells you the encoding algorithm, the possible values are listed in the manpage for pdfimages.

2015/11/18
7
11/18/2015 8:33:00 PM