pdf

Compressing pdf

1. Type the following command (source)$ gs -dNOPAUSE -dBATCH -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -dPDFSETTINGS=setting -sOutputFile=output.pdf input.pdf

2. Set the input file name properly as well as the output file name if wanted.

3. in -dPDFSETTINGS use:

   • /screen for lowest quality

   • /ebook for medium quality

   • /printer and /prepress for high quality

Modifying a pdf

• command $ convert input.pdf output.pdf

  • Options:

    • density image resolution

    • rotate rotation angle degrees

    • attenuate noise addition

    • noise noise peak reduction

    • flatten no virtual offline across layers

    • sharpen Gaussin operator to sharpen the image

  • Example (source): $ convert -density 150 input.pdf -rotate "$([ $((RANDOM % 2)) -eq 1 ] && echo -)0.$(($RANDOM % 3))" -attenuate 0.15 +noise Multiplicative -flatten -attenuate 0.02 +noise Multiplicative -sharpen 0x1.0 output.pdf

Metadata info of a pdf

• command pdfinfo: $ pdfinfo file.pdf