Thanks Doug,
When I run
tkregister2 --targ structuralimage --mov functionalimage --reg register.dat
I got the following error.
====================== target volume XXXXX.img movable volume XXXXXX.img reg file register.dat LoadVol 1 $Id: tkregister2.c,v 1.22 2003/11/05 21:30:50 greve Exp $ Diagnostic Level -1 regio_read_register(): No such file or directory Could not open register.dat Segmentation fault (core dumped) ==========================
What could have been wrong? Thanks. Nam.