Branch of
image processing which treats images as
sets. Started by the works of
Jean Serra and
G. Matheron,
mathematical morphology tried to model
geological processes (that explains the name of operations like
erosion).
Most morphological operations take an image and an structuring element and, for each pixel of the image, an environment around it (with the structuring element's shape) is considered, and then some operation is made (the maximum of the environment for erosion or the minimum for dilatation).
Some other morphological operations are openings (erosion then dilatation), closings (the opposite), watersheds (which divides the image in influence regions of local maximums and minimums, very useful for segmentation), thickening and thinning and many others.