The Sobel operator
Better approximations of the derivatives exist
•The
Sobel operators below are very commonly used
1
0
-1
2
0
-2
1
0
-1
-1
-2
-1
0
0
0
1
2
1
•The
standard defn. of the Sobel operator omits the 1/8 term
–doesn’t
make a difference for edge detection
–the
1/8 term is needed to get the right gradient value, however
