Compress pdf file with linux

A pdf file with a lot of scanned images can be a very large file.

I reduced a file from 307MB to 68MB with limited quality loss.

The original askubuntu answer.

Use the following ghostscript command:

    gs -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -dPDFSETTINGS=/screen -dNOPAUSE -dQUIET -dBATCH -sOutputFile=output.pdf input.pdf

• -dPDFSETTINGS=/screen lower quality, smaller size.
• -dPDFSETTINGS=/ebook for better quality, but slightly larger pdfs.
• -dPDFSETTINGS=/prepress output similar to Acrobat Distiller “Prepress Optimized” setting
• -dPDFSETTINGS=/printer selects output similar to the Acrobat Distiller “Print Optimized” setting
• -dPDFSETTINGS=/default selects output intended to be useful across a wide variety of uses, possibly at the expense of a larger output file

I tested this approach with a document full of scanned pages. The original file was 306.7MB, the results of the different quality setting are: