I really hate it when people mail me super large pdf files and therefore I myself compress them before I send them out. Unfortunately, the build-in OS X Scanner application does not provide pdf compression. Luckily, there is Ghostscript and someone already wrote a small script to make this process handy.

This script worked for me most of the time but I always got a warning and sometimes it just crashed:

SetUseCIEColor for UseDeviceIndependentColor to work properly
Unrecoverable error: stackunderflow in .setdistillerparams

After adding -dUseCIEColor I got rid of them and the script now looks as follows