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