Source: https://askubuntu.com/questions/113544/how-can-i-reduce-the-file-size-of-a-scanned-pdf-file
Anything to add? Let's talk @kgoutsos. Share this page on Twitter, Facebook, LinkedIn or use the permalink.Reducing PDF filesize on Linux
Compressing PDFs with GhostScript:
gs -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -dPDFSETTINGS=/screen -dNOPAUSE -dQUIET -dBATCH -sOutputFile=output.pdf input.pdf
-dPDFSETTINGS=/screenlower quality, smaller size. (72 dpi)-dPDFSETTINGS=/ebookfor better quality, but slightly larger pdfs. (150 dpi)-dPDFSETTINGS=/prepressoutput similar to Acrobat Distiller “Prepress Optimized” setting (300 dpi)-dPDFSETTINGS=/printerselects output similar to the Acrobat Distiller “Print Optimized” setting (300 dpi)-dPDFSETTINGS=/defaultselects output intended to be useful across a wide variety of uses, possibly at the expense of a larger output file