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