Crop a 2D filterbank (adjusting filter norms). Takes a filter bank and crops it by cropping off delta from each side. Ensuresthat the mean response of each filter is 0 and that the L1 norm is 1, i.e. sum(sum(abs(F)))==1. INPUTS FB - original filterbank delta - amount to crop by OUTPUTS FBC - cropped filterbank DATESTAMP 29-Sep-2005 2:00pm