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