Parts of visual form: computational aspects

A proposed general principle of form from function motivates a particular partitioning scheme involving two types of parts, neck-based and limb-based. Neck-based parts arise from narrowings in shape, or the local minima in distance between two points on the boundary, while limb-based parts arise from a pair of negative curvature extrema which have co-circular tangents. Computational support for the limb-based and neck-based parts is presented by showing that they are invariant, robust, stable, and yield a hierarchy of parts. Examples illustrate that the resulting decompositions are robust in the presence of occlusion and noise for a range of man-made and natural objects and that they lead to natural and intuitive parts which can be used for recognition