python3 image-rotator.py -h
usage: image-rotator.py [-h] [-i INPUT] [-o OUTPUT] [-u [UNDO]]
                        [--magnitude MAGNITUDE]

optional arguments:
  -h, --help            show this help message and exit
  -i INPUT, --input INPUT
                        source image filename
  -o OUTPUT, --output OUTPUT
                        destination filename
  -u [UNDO], --undo [UNDO]
                        undo the transformation [y/n]
  --magnitude MAGNITUDE
                        amount to rotate, warning, advanced