Tool Laplacian Filter

The Laplacian filter is a high-pass filter operator that is commonly used for edge detection. Also referred to as Laplacian of Gaussian (LoG) or Marr-Hildreth-Operator.
The kernel can be defined by search radius and weighting function adjustment or be chosen from predefined standards.

Standard kernel 1 (3x3):

0	-1	0
-1	4	-1
0	-1	0

Standard kernel 2 (3x3):

-1	-1	-1
-1	8	-1
-1	-1	-1

Standard kernel 3 (3x3):

-1	-2	-1
-2	12	-2
-1	-2	-1

Author: A.Ringeler (c) 2003, O.Conrad (c) 2008
Menu: Grid|Filter
WIKI: http://sourceforge.net/apps/trac/saga-gis/wiki/grid_filter_2

Parameters

	Name	Type	Identifier	Description	Constraints
Input	Grid	grid, input	`INPUT`	-	-
Output	Filtered Grid (*)	grid, output, optional	`RESULT`	-	-
Options	Grid System	grid system	`PARAMETERS_GRID_SYSTEM`	-	-
	Method	choice	`METHOD`	-	Available Choices: [0] standard kernel 1 [1] standard kernel 2 [2] Standard kernel 3 [3] user defined kernel Default: 3
	Kernel Radius	integer number	`KERNEL_RADIUS`	-	Minimum: 1 Default: 2
	Standard Deviation	floating point number	`SIGMA`	The standard deviation as percentage of the kernel radius.	Minimum: 1.000000 Default: 50.000000
(*) optional

Command-line

Usage: saga_cmd grid_filter 2 [-INPUT <str>] [-RESULT <str>] [-METHOD <str>] [-KERNEL_RADIUS <num>] [-SIGMA <double>]
  -INPUT:<str>        	Grid
	grid, input
  -RESULT:<str>       	Filtered Grid
	grid, output, optional
  -METHOD:<str>       	Method
	choice
	Available Choices:
	[0] standard kernel 1
	[1] standard kernel 2
	[2] Standard kernel 3
	[3] user defined kernel
	Default: 3
  -KERNEL_RADIUS:<num>	Kernel Radius
	integer number
	Minimum: 1
	Default: 2
  -SIGMA:<double>     	Standard Deviation
	floating point number
	Minimum: 1.000000
	Default: 50.000000