Erode (“narrowing” or “washing-out”) — together with such transformations as dilate, opening and closing is on of the main operations of mathematical morphology. This is the operation inverted to the dilatation operation.
The Erode filter decreases the image area leading to the thinning of pixels making broader and stronger light areas in the image. The idea of this transformation is that unwanted contamination and noises are washed out, and big, that means, significant areas of image are not changed.
This is the operation of finding local maximum on some environs which is set by structure-forming element.
Size (size) parameter indicates the circle of the filter influence around each point.
Iteration (iteration) parameter indicates the amount of iterations.