D2FDXDY filter
The D2FDXDY filter is standard a linear filter which works in a 5 by 5 environment. It calculates the second derivative in all diagonal directions (d2f/dxdy). The values in the matrix are:
-1 |
8 |
0 |
-8 |
1 |
|
8 |
-64 |
0 |
64 |
-8 |
|
0 |
0 |
0 |
0 |
0 |
|
-8 |
64 |
0 |
-64 |
8 |
|
1 |
-8 |
0 |
8 |
-1 |
Gain factor = 1/144 = 0.0069444
When using the D2FDXDY filter on a DEM:
See also:
Filter types: gradient or derivative filters (technical information)