Morphological decomposition of 2-D binary shapes into modestly overlapped disk components

A generalized skeleton transform was recently introduced which allows a shape to be represented as a collection of modestly overlapped octagonal shape parts. However, the generalized skeleton transform needs to be applied many times. Furthermore, an octagonal component is not easily matched up with another octagonal component from a different shape. In this paper, we describe a new "distance" transform which identifies a special maximal octagon for each image point in a given shape. This transform leads to the development of a new shape decomposition algorithm. This algorithm is more efficient to implement; the "distance" transform only needs to be applied once. The disk components used in the new algorithm are more primitive than octagons and easily matched up with other disk components from another shape. The experiments show that the new decomposition algorithm produces as efficient representations as the old algorithm.