Usage: Atlas viewer and ROIs selector

Options:
  -h, --help            show this help message and exit
  -i FILE, --input=FILE
                        input model/atlas graph[s] (.arg). Selveral items
                        allowed.
  -v FILE, --volume=FILE
                        volume which may be viewed optionally
  -s FILE, --sel=FILE   selection file for pre-selected regions/groups
  -n FILE, --nomenclature=FILE
                        nomenclature file (.hie) for names and colors