-11-
²Recipe for intra-subject S2-to-S1 transformation:
1.Compute S2-to-S1 transformation:
å3dvolreg -twopass -clipit -zpad 4 -base S1+orig \         -prefix S2reg  S2+orig
åRotation/shift parameters are saved in S2reg+orig.HEAD
2.If not done before (e.g., in to3d), zero pad E1 datasets:
å3dZeropad -z 4 -prefix E1pad  E1+orig
3.Register E1 datasets within the session:
å3dvolreg -clipit -base ÔE1pad+orig[4]Õ -prefix E1reg \   E1pad+orig
4.Register E2 datasets within the session, at the same time executing larger rotation/shift to session 1 coordinates that were saved in S2reg+orig.HEAD:
å3dvolreg -clipit -base ÔE2+orig[4]Õ \    -rotparent S2reg+orig      \
å  -gridparent E1reg+orig\
å  -prefix E2reg  E2reg+orig
å-rotparent tells where the inter-session transformation comes from
å-gridparent defines the output grid location/size of new dataset
íOutput dataset will be shifted and zero padded as needed to lie on top of E1reg+orig