Morphological skeleton representation and shape recognition

The nature of the morphological skeleton representation of a binary shape is related to the composition of structuring elements through the distance function defined by morphological set transforms in digital space. Two digital metrics, uniform-step distance and periodically-uniform-step distance, are introduced to provide useful spatial measures for morphological transforms. A natural shape representation by ribbonlike components is accomplished by extraction of skeletal feature primitives from the morphological skeleton of a shape. The hierarchical structure of the representation makes it stable and insensitive to noise disturbance. The matching is a simple top-down process in which the inverses of the skeletal feature primitives at each level are compared. The recognition is based on the similarity measure provided by the matching process