ABSTRACT
This chapter reviews the three major categories of shape description methods: contour, interior regions, and structure. Contour methods describe the shape by qualitative measures of the perimeter. Some of these methods only work well for simple shapes, and many have limitations on their performance. A particular object has expected relationships among its components. The process of Fourier descriptors is a method that attempts to capture the relative shape of an object. The elements of a vector are the energies of the individual quadrants of the decomposition. Each image creates a shape description vector, and vectors for different images can be compared by employing the user's desired metric. One approach is to use curvature flow, which considers the localized curvatures of the shape. The flow is the action of changing that shape such that the border of the shape moves toward the local center of curvature.
