This question already has an answer here:

Background is that in my lab it is common and convenient to document stuff by simply making a picture of it. Once a project is finished, I will merge these pictures into one file which I will give to other group members so they can work with it. Since these files often contain 20+ images where each image is a few Mb the PDF-File gets quite large (>100Mb).

That is why I am wondering: Is there any convenient way in LaTex to lower the resolution of pictures without having to run them through another software beforehand ?

marked as duplicate by John Kormylo, TeXnician, Mensch, Stefan Pinnow, user31729 Apr 15 '18 at 6:26

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

  • I would not consider this a duplicate since both answers suggest using additional software beforehand/afterwards. – Christian Apr 9 '18 at 21:01
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    Changind image resolution is a task for an image editor. I doubt Tex or pdflatex can do it properly, – omisson Apr 9 '18 at 21:10
  • @Christian you are right that the answers in the other question use additional software, however it can be fully automated from within your LaTeX file, so it might be a suitable approach for your issue. – Marijn Apr 9 '18 at 21:39
  • For PDFTeX there are settings like \pdfpxdimen which is a TeX length. You can set the DPI with it, but it might just scale the image instead of reducing its file size. – Martin Scharrer Apr 10 '18 at 6:14