14
Cross-correlation filtering
Let’s write this
down as an equation. Assume the averaging window is
(2k+1)x(2k+1):
We can
generalize this idea by allowing different weights for different neighboring
pixels:
This is
called a cross-correlation operation and written:
H
is called the “filter,” “kernel,” or “mask.”
The above
allows negative filter indices. When you implement need
to use: H[u+k,v+k] instead of H[u,v]
