Mac OS X Preview wastes space with bitmap PDFs – a work-around

This happened to me recently: I had an 11MB bitmap PDF and wanted to rotate all pages. After I did that and saved it, its size had grown to 31MB. I did some searching and found a way to do this with a command line tool: pdftk. With pdftk, the file stayed the same size after rotation.
  • You can install it on Mac OS via Fink or MacPorts.
  • This is how you rotate an entire document by 180°: pdftk in.pdf cat 1-endS output out.pdf
    • Explanation: cat means processing a file, 1-end selects pages, S rotates the selected pages.
    • The options for rotation are: N: 0°, E: 90°, S: 180°, W: 270°.
  • pdftk can do much more: merge files, remove pages, split files, etc.