Module 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:
- 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.
- Author: O.Conrad (c) 2015
- Specification: grid
- Menu: Grid|Filter
Parameters
| | Name | Type | Identifier | Description | Constraints |
|---|
| Input | Grid | Grid (input) | GRID | - | - |
| Output | Edge Points | Shapes (output) | EDGE_POINTS | - | - |
| Edge Segments | Shapes (output) | EDGE_LINES | - | - |
| Grids (*) | Grid list (optional output) | GRIDS | - | - |
| Options | Minimum Magnitude | Floating point | TMAGNITUDE | Minimum magnitude as percentile. | Minimum: 0.000000
Maximum: 100.000000
Default: 90.000000 |
| Maximum Angle | Floating point | TDIRECTION | Maximum angular difference as degree between adjacent segment points. | Minimum: 0.000000
Maximum: 180.000000
Default: 10.000000 |
| Output of Grids | Boolean | GRIDS_SHOW | - | Default: 0 |
| (*) optional |
Command-line
Usage: saga_cmd grid_filter 16 [-GRID <str>] [-EDGE_POINTS <str>] [-EDGE_LINES <str>] [-TMAGNITUDE <str>] [-TDIRECTION <str>] [-GRIDS_SHOW <str>] [-GRIDS <str>]
-GRID:<str> Grid
Grid (input)
-EDGE_POINTS:<str> Edge Points
Shapes (output)
-EDGE_LINES:<str> Edge Segments
Shapes (output)
-TMAGNITUDE:<str> Minimum Magnitude
Floating point
Minimum: 0.000000
Maximum: 100.000000
Default: 90.000000
-TDIRECTION:<str> Maximum Angle
Floating point
Minimum: 0.000000
Maximum: 180.000000
Default: 10.000000
-GRIDS_SHOW:<str> Output of Grids
Boolean
Default: 0
-GRIDS:<str> Grids
Grid list (optional output)