Geodesic Morphological Reconstruction

Author(s)	HfT Stuttgart (c) 2013
Library ID	grid_filter
Tool ID	12
Version	1.0
Menu	Grid \| Filter

Description

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

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.	-
Output	Objects	grid, output, optional	`OBJECT_GRID`	Binary object mask	-
Options	Grid System	grid system	`PARAMETERS_GRID_SYSTEM`	-	-
	Shift Value	floating point number	`SHIFT_VALUE`	-	Default: 5.000000
	Preserve 1px border	boolean	`BORDER_YES_NO`	-	Default: 1
	Threshold	floating point number	`THRESHOLD`	Threshold for object identification.	Minimum: 0.000000 Default: 1.000000

Command Line


Usage: saga_cmd grid_filter 12 [-INPUT_GRID ] [-DIFFERENCE_GRID ] [-OBJECT_GRID ] [-SHIFT_VALUE ] [-BORDER_YES_NO ] [-THRESHOLD ]
  -INPUT_GRID:        Input Grid
	grid, input
  -DIFFERENCE_GRID:   Morphological Reconstruction
	grid, output
  -OBJECT_GRID:       Objects
	grid, output, optional
  -SHIFT_VALUE:    Shift Value
	floating point number
	Default: 5.000000
  -BORDER_YES_NO:     Preserve 1px border
	boolean
	Default: 1
  -THRESHOLD:      Threshold
	floating point number
	Minimum: 0.000000
	Default: 1.000000