Shrink the file size of a pdf?

Shrink the file size of a pdf? Use the following command. ebook has a good balance between the file size and the image quality. screen compresses the images too much.

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

-dPDFSETTINGS=configuration

Presets the "distiller parameters" to one of four predefined settings:

• /screen selects low-resolution output similar to the Acrobat Distiller "Screen Optimized" setting.
• /ebook selects medium-resolution output similar to the Acrobat Distiller "eBook" setting.
• /printer selects output similar to the Acrobat Distiller "Print Optimized" setting.
• /prepress selects output similar to Acrobat Distiller "Prepress Optimized" setting.
• /default selects output intended to be useful across a wide variety of uses, possibly at the expense of a larger output file.