{TAIL ~ The method} 19 wherein the function is a logical function including {HEAD ~ the minimum} or maximum of the height and gray scale values 
{ TAIL ~ The method } 19 wherein the function is a logical function including { HEAD ~ the minimum } or maximum of the height and gray scale values
TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH