Tool Name	Wombling for Multiple Features (Edge Detection)
Tool ID	17
Library ID	grid_filter
Version	1.0
Author(s)	O.Conrad (c) 2015

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	grid list, output, optional	OUTPUT
Options
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