section "Transform (Note that only one of --control, --spacing is required. The other will be adjusted to fit the region and allow exact representation. SamplingFactor will be set accordingly"
option "initMatrix" - "Prior rigid/affine transform matrix from reference to target space" string no
+option "centre" - "Centre images before starting registration (ignored if initMatrix was given)" flag off
option "initCoeff" - "Initial coefficient image" string no
option "order" - "Spline Order FFD" int no multiple default="3"
option "control" - "Internal control points for each dimension" int no multiple