DICOM gantry tilt correction

Checks for gantry tilt in DICOM fileset and modifies the images

This is a modified version of a script uploaded by the user Denny. I grabbed a copy and unfortunately found it didn't work for me. So, I modified it and made some improvements.

Improvements include:

- Some timing code to show you how long it took to process each slice (average time only)
- Progress indicators (slice by slice)
- Removed quite a bit of redundant code, hopefully making it a little quicker
- Changed the image translation method to use a transformation matrix instead. Hopefully this will allow for a bit more flexibility with future modifications of the script, and performing different image manipulations

The same caveats apply to the original script regarding subdirectories etc, so I would advise you check it if you have any problems using this one. When I get some time I'll add some better error handling! Search for 'DICOM gantry tilt' and you'll find it (although you probably already did!)

Enjoy!

Phil