ANTSJacobian - part of ANTS registration suite
ANTSJacobian ImageDim gWarp outfile uselog maskfn normbytotalbool
use-2nd-order-central-difference-boolean
for example ANTSJacobian 3 myWarp.nii Output 1
templatebrainmask.nii 1 the last 1 normalizes the jacobian by
the total in the mask. use this to adjust for head size.