Type of transformation to be optimized

There are a number of different transformations that can be optimized. Each one is specified by a flag on the command line. This information is used internally to control the number of the parameters that are modified by the optimization algorithm. (Only the resulting transformation matrix is returned in the output .xfm file.) The default is the -procrustes transformation.

The choices are:

-pat

return the matrix determined by the principal axes transformation.

-lsq6

return the six parameter registration matrix. the six parameters are translation x,y,z and rotation x,y,z.

-lsq7

return the seven parameter registration matrix. the parameters are translation x,y,z and rotation x,y,z and one global scale.

-lsq9

return the seven parameter registration matrix. the parameters are translation x,y,z and rotation x,y,z and scale x,y,z.

-lsq12

return full 12 parameter transformation. the parameters are translation x,y,z; rotation x,y,z; scale x,y,z and shear x,y,z.

-procrustes

same as -lsq7

The user can also specify whether the forward (from source to model) or inverse (from model to source) transformation should be recovered. These flags are:

-forward

Recover forward transformation (source -> model, default).

-invert

Recover inverted transformation (model -> source).