The local reference point is then adjusted as a function of {HEAD ~ the input value} of {TAIL ~ each constant area pixel} 
of
The local reference point is then adjusted as a function of { HEAD ~ the input value } of { TAIL ~ each constant area pixel }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL