What I actually want to achieve is, the result I get when printing to pdf from Okular and clicking on force rasterization and print annotations. However, I would like to do this from the terminal (my ultimate goal is to create a dolphin service menu for this).
convert seems to rasterize pdfs on the terminal. So
convert -density 300 infile.pdf outfile.pdf would do the trick. Convert is provided by Imagemagick , so you would need to install that first. The file will be quite large but you can reduce its size with gostscript (e.g.
gs -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -dPDFSETTINGS=/ebook -dNOPAUSE -dQUIET -dBATCH -sOutputFile=outfile.pdf infile.pdf or by trying some other answer from here)
A service menu for the rasterization would look like this:
[Desktop Entry] Type=Service ServiceTypes=KonqPopupMenu/Plugin MimeType=application/pdf Icon=acroread Actions=rasterizepdf; [Desktop Action rasterizepdf] Name=rasterize pdf Icon=acroread Exec=convert -density 300 %u "$(dirname "%u")/$(basename "%u" .pdf)_r.pdf"
Save it in
~/.local/share/kservices5/ServiceMenus/ as a .desktop file. Of course you can also create a service menu for shrinking the pdf afterwards.