Tool Name	Binary Erosion-Reconstruction
Tool ID	13
Library ID	grid_filter
Version	1.0
Author(s)	HfT Stuttgart (c) 2013

Description

Common binary opening does not guarantee, that foreground regions which outlast the erosion step are reconstructed to their original shape in the dilation step. Depending on the application, that might be considered as a deficiency. Therefore this tool provides a combination of erosion with the binary Geodesic Morphological Reconstruction, see Vincent (1993). Here we use the algorithm on p. 194: Breadth-first Scanning.

The marker is defined as the eroded input grid, whereas the mask is just the input grid itself. The output grid is the reconstruction of the marker under the mask.

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	Grid to be filtered
Output
Output Grid	grid, output	OUTPUT_GRID	Reconstruction result
Options
Filter Size (Radius)	integer number	RADIUS	Filter size (radius in grid cells)	Default: 3