Is it possible to find out what compression algorithms have been used for images in a PDF document?
Answer
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.
Attribution
Source : Link , Question Author : Shannon Matthews , Answer Author : azrdev