Graphics Reference
In-Depth Information
6. The result of applying the two Sobel edge-detection filters can be seen in the
following figure:
Left: Sobel filter, Right: 3x3 Blur + Sobel filter
How it works…
The Sobel filter is the combination of applying a formula to determine the gradient magnitude
of two convolution kernels (the second is the first rotated counter-clockwise), and then
checking the result against a provided threshold. If it passes the test, it is an edge (black),
otherwise it is left blank (white).
The following formula is a faster approximation of the more complete Sobel gradient
magnitude formula:
Faster approximation of the Sobel gradient magnitude formula
