incrementing {TAIL ~ 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 said image 
incrementing { TAIL ~ 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 said image
OTH TAIL TAIL TAIL TAIL TAIL TAIL 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 OTH OTH