option "vf" - "Result DVF" string yes
option "coeff" - "Result coefficient images" string no
+option "coeffEveryN" - "Result coefficient images at every N iterations (requires --coeff and --verbose)" int no default="20"
option "output" o "Deformed target image" string yes
option "before" - "Difference image before (but after rigid transform)" string no
option "after" - "Difference image after " string no