Synopsis
		sffbdip < in.rsf > out.rsf rect1=0 rect2=0 niter=5 liter=20 radius=1.0 eta=0.75 idip=0.0 verb=n

Parameters
		float eta=0.75 steps for iteration   float idip=0.0 initial dip   int liter=20 number of linear iterations   int niter=5 number of iterations   float radius=1.0 interpolating radius for opwd   int rect1=0 dip smoothness on 1st axis   int rect2=0 dip smoothness on 2nd axis   bool verb=n [y/n] verbosity flag