Wombling for Multiple Features (Edge Detection)

Author: O.Conrad (c) 2015
Menu: Grid | Filter

Description

Continuous Wombling for edge detection. Uses magnitude of gradient to detect edges between adjacent cells. Edge segments connect such edges, when the difference of their gradient directions is below given threshold.

References

Fitzpatrick, M.C., Preisser, E.L., Porter, A., Elkinton, J., Waller, L.A., Carlin, B.P., Ellison, A.M. (2010): Ecological boundary detection using Bayesian areal wombling. Ecology 91(12): 3448-3455. doi:10.1890/10-0807.1.
Fortin, M.-J. and Dale, M.R.T (2005): Spatial Analysis - A Guide for Ecologists. Cambridge University Press.

Parameters

	Name	Type	Identifier	Description	Constraints
Input	Features	grid list, input	`FEATURES`	-	-
Output	Edges	grid list, output	`EDGE_CELLS`	-	-
Output	Output	grid list, output, optional	`OUTPUT`	-	-
Options	Grid System	grid system	`PARAMETERS_GRID_SYSTEM`	-	-
	Minimum Magnitude	floating point number	`TMAGNITUDE`	Minimum magnitude as percentile.	Minimum: 0.000000 Maximum: 100.000000 Default: 90.000000
	Maximum Angle	floating point number	`TDIRECTION`	Maximum angular difference as degree between adjacent segment points.	Minimum: 0.000000 Maximum: 180.000000 Default: 30.000000
	Minimum Neighbours	integer number	`TNEIGHBOUR`	Minimum number of neighbouring potential edge cells with similar direction.	Minimum: 0 Default: 1
	Alignment	choice	`ALIGNMENT`	-	Available Choices: [0] between cells [1] on cell Default: 1
	Edge Connectivity	choice	`NEIGHBOUR`	-	Available Choices: [0] Rooke's case [1] Queen's case Default: 1
	Additional Output	choice	`OUTPUT_ADD`	-	Available Choices: [0] none [1] gradients [2] edge cells Default: 0
	Zero as No-Data	boolean	`ZERO_AS_NODATA`	-	Default: 1

Command Line


Usage: saga_cmd grid_filter 17 [-TMAGNITUDE ] [-TDIRECTION ] [-TNEIGHBOUR ] [-ALIGNMENT ] [-NEIGHBOUR ] [-FEATURES ] [-EDGE_CELLS ] [-OUTPUT_ADD ] [-OUTPUT ] [-ZERO_AS_NODATA ]
  -TMAGNITUDE:
                          Minimum Magnitude
                          	floating point number
                          	Minimum: 0.000000
                          	Maximum: 100.000000
                          	Default: 90.000000
  -TDIRECTION:
                          Maximum Angle
                          	floating point number
                          	Minimum: 0.000000
                          	Maximum: 180.000000
                          	Default: 30.000000
  -TNEIGHBOUR:       Minimum Neighbours
	integer number
	Minimum: 0
	Default: 1
  -ALIGNMENT:        Alignment
	choice
	Available Choices:
	[0] between cells
	[1] on cell
	Default: 1
  -NEIGHBOUR:        Edge Connectivity
	choice
	Available Choices:
	[0] Rooke's case
	[1] Queen's case
	Default: 1
  -FEATURES:         Features
	grid list, input
  -EDGE_CELLS:       Edges
	grid list, output
  -OUTPUT_ADD:
                          Additional Output
                          	choice
                          	Available Choices:
                          	[0] none
                          	[1] gradients
                          	[2] edge cells
                          	Default: 0
  -OUTPUT:           Output
	grid list, output, optional
  -ZERO_AS_NODATA:   Zero as No-Data
	boolean
	Default: 1