1. A computer program embodied in a computer-readable medium for comparing at least two sets of multimedia data with shape information so as to provide a dissimilarity measure between the sets, a first set forming a reference set and the second set being compared relative to the first set, comprising: a) a first set of instructions for providing shape information in the form of a set of approximately equidistant contour points for each set of multimedia data; b) a second set of instructions for associating the contour points of the first set with contour points of the second set so as to define associated contour points; and c) a third set of instructions for calculating distances between said associated contour points, wherein the distances between said associated contour points are used to determine a dissimilarity measure between said sets of multimedia data, thereby providing an indicator of the degree of similarity between the sets.