I use Mac OS X Snow Leopard. I have a PDF with form fields, annotations, and stamps on it. I would like to freeze (or "flatten") that PDF so that the form fields can't be changed and the annotations/stamps are no longer editable. Since I actually have many of these PDFs, I want to do this automatically on the command line.

Some things I've tried/considered, with their degree of success:

• Open in Preview and Print to File. This creates a totally flat PDF without changing the file size. The only way to automate seems to be to write a kludgy UI-based AppleScript, though, which I've been trying to avoid.
• Open in Acrobat Pro and use a JavaScript function to flatten. Again, not sure how to automate this on the command line.
• Use pdftk with the flatten option. But this only flattens form fields, not stamps and other annotations.
• Use cupsfilter which can create PDF from many file formats. Like pdftk this flattened only the form fields.
• Use cups-pdf to hook into the Mac's printserver and save a PDF file instead of print. I used the macports version. The resulting file is flat but huge. I tried this on an 8MB file; the flattened PDF was 358MB! Perhaps this can be combined with a ghostscript call as in Ubuntu Tip:Howto reduce PDF file size from command line.

Any other suggestions would be appreciated.