This function is used to calculate the deformation field corresponding to a specified linear or nonlinear transformation. The deformation field gives the location in source image space corresponding to the centre of each voxel in target space. It is used as a common form for linear and nonlinear transformations, and allows them to be visualised.
deformationField(transform, jacobian = TRUE)A logical value: if TRUE, a Jacobian determinant map
is also calculated and returned in an attribute.
An "internalImage" representing the deformation field. If
requested, the Jacobian map is stored in an attribute, which can be
extracted using the jacobian accessor function.