This class implements the erosion filter.
The kernel size is fixed with a diameter of 3 pixels. This
makes sense the operation gets rapidly computationally more
expensive with increasing diameter. Computational complexity
is related to the third power of the diameter, so 2-fold
diameter means 8-fold computation time.
For complexity reasons, the implementation uses a 6-neighbour-
hood and not a 27-neighborhood.
Fields inherited from interface ij.plugin.filter.PlugInFilter