SAGA-GIS Tool Library Documentation (v7.2.0)

Tool Wombling (Edge Detection)

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


Parameters

 NameTypeIdentifierDescriptionConstraints
InputFeatureGrid (input)FEATURE--
OutputEdge Points (*)Shapes (optional output)EDGE_POINTS--
Edge Segments (*)Shapes (optional output)EDGE_LINES--
Gradients (*)Grid list (optional output)GRADIENTS--
OptionsGrid systemGrid systemPARAMETERS_GRID_SYSTEM--
Minimum MagnitudeFloating pointTMAGNITUDEMinimum magnitude as percentile.Minimum: 0.000000
Maximum: 100.000000
Default: 90.000000
Maximum AngleFloating pointTDIRECTIONMaximum angular difference as degree between adjacent segment points.Minimum: 0.000000
Maximum: 180.000000
Default: 30.000000
Minimum NeighboursIntegerTNEIGHBOURMinimum number of neighbouring potential edge cells with similar direction.Minimum: 0
Default: 1
AlignmentChoiceALIGNMENT-Available Choices:
[0] between cells
[1] on cell
Default: 1
Edge ConnectivityChoiceNEIGHBOUR-Available Choices:
[0] Rooke's case
[1] Queen's case
Default: 1
Output of GradientsBooleanGRADIENTS_OUT-Default: 0
(*) optional

Command-line

Usage: saga_cmd grid_filter 16 [-TMAGNITUDE <double>] [-TDIRECTION <double>] [-TNEIGHBOUR <num>] [-ALIGNMENT <str>] [-NEIGHBOUR <str>] [-FEATURE <str>] [-EDGE_POINTS <str>] [-EDGE_LINES <str>] [-GRADIENTS_OUT <str>] [-GRADIENTS <str>]
  -TMAGNITUDE:<double>	Minimum Magnitude
	Floating point
	Minimum: 0.000000
	Maximum: 100.000000
	Default: 90.000000
  -TDIRECTION:<double>	Maximum Angle
	Floating point
	Minimum: 0.000000
	Maximum: 180.000000
	Default: 30.000000
  -TNEIGHBOUR:<num>   	Minimum Neighbours
	Integer
	Minimum: 0
	Default: 1
  -ALIGNMENT:<str>    	Alignment
	Choice
	Available Choices:
	[0] between cells
	[1] on cell
	Default: 1
  -NEIGHBOUR:<str>    	Edge Connectivity
	Choice
	Available Choices:
	[0] Rooke's case
	[1] Queen's case
	Default: 1
  -FEATURE:<str>      	Feature
	Grid (input)
  -EDGE_POINTS:<str>  	Edge Points
	Shapes (optional output)
  -EDGE_LINES:<str>   	Edge Segments
	Shapes (optional output)
  -GRADIENTS_OUT:<str>	Output of Gradients
	Boolean
	Default: 0
  -GRADIENTS:<str>    	Gradients
	Grid list (optional output)