Tool Geodesic Morphological Reconstruction
Geodesic morphological reconstruction according to Vincent (1993). Here we use the algorithm on p. 194: Computing of Regional Maxima and Breadth-first Scanning.
A marker is derived from the input grid by subtracting a constant shift value. Optionally, the shift value can be set to zero at the border of the grid ("Preserve 1px border Yes/No" parameter). The final result is a grid showing the difference between the input image and the morphological reconstruction of the marker under the input image. If the Option "Create a binary mask" is selected, the difference grid is thresholded with provided threshold value to create a binary image of maxima regions.
References
- Arefi, H., Hahn, M. (2005): A Morphological Reconstruction Algorithm for Separating Off-Terrain Points from Terrain Points in Laser Scanning Data. Proceedings of the ISPRS Workshop Laser Scanning 2005, Enschede, the Netherlands, September 12-14, 2005 PDF.
- Vincent, L. (1993): Morphological Grayscale Reconstruction in Image Analysis: Applications and Efficient Algorithms. IEEE Transactions on Image Processing, Vol. 2, No 2. doi: 10.1109/83.217222.
- Author: HfT Stuttgart (c) 2013
- Menu: Grid|Filter
Parameters
| | Name | Type | Identifier | Description | Constraints |
|---|
| Input | Input Grid | Grid, input | INPUT_GRID | Input for the morphological reconstruction | - |
| Output | Morphological Reconstruction | Grid, output | DIFFERENCE_GRID | Reconstruction, difference to input grid. | - |
| Objects (*) | Grid, output, optional | OBJECT_GRID | Binary object mask | - |
| Options | Grid System | Grid system | PARAMETERS_GRID_SYSTEM | - | - |
| Shift Value | Floating point | SHIFT_VALUE | - | Default: 5.000000 |
| Preserve 1px border | Boolean | BORDER_YES_NO | - | Default: 1 |
| Threshold | Floating point | THRESHOLD | Threshold for object identification. | Minimum: 0.000000
Default: 1.000000 |
| (*) optional |
Command-line
Usage: saga_cmd grid_filter 12 [-INPUT_GRID <str>] [-DIFFERENCE_GRID <str>] [-OBJECT_GRID <str>] [-SHIFT_VALUE <double>] [-BORDER_YES_NO <str>] [-THRESHOLD <double>]
-INPUT_GRID:<str> Input Grid
Grid, input
-DIFFERENCE_GRID:<str> Morphological Reconstruction
Grid, output
-OBJECT_GRID:<str> Objects
Grid, output, optional
-SHIFT_VALUE:<double> Shift Value
Floating point
Default: 5.000000
-BORDER_YES_NO:<str> Preserve 1px border
Boolean
Default: 1
-THRESHOLD:<double> Threshold
Floating point
Minimum: 0.000000
Default: 1.000000