a first set of zero coefficients extending along {HEAD ~ a direction} traversing said filter through {TAIL ~ a center position} to form a first side and a second side 
a first set of zero coefficients extending along { HEAD ~ a direction } traversing said filter through { TAIL ~ a center position } to form a first side and a second side
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH