incrementing said position of said edge detection filter in {HEAD ~ the first direction}, wherein the incremented position is associated with pixels of a next row of {TAIL ~ said image} 
incrementing said position of said edge detection filter in { HEAD ~ the first direction } , wherein the incremented position is associated with pixels of a next row of { TAIL ~ said image }
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL