Patent ID: 7212673

Claim:
A computer accessible memory medium that stores program instructions for determining an underlying rotational symmetry group of a configuration of discrete curves, wherein the program instructions are executable to perform: receiving a configuration of discrete closed curves; determining a plurality of configuration rotational symmetry sub-groups of the configuration, wherein each of the plurality of configuration rotational symmetry sub-groups is associated with one or more of the discrete curves, and wherein the plurality of configuration rotational symmetry sub-groups are based on each discrete curve's distance from a configuration center of mass, equivalence class, rotational symmetry group, and sub-configuration rotational symmetry group, wherein a rotational symmetry group of one indicates no rotation symmetry; and if no discrete curves having a distance from the configuration center of mass of substantially zero also have a rotational symmetry group of one: computing a greatest common divisor (GCD) of the plurality of configuration rotational symmetry sub-groups, wherein the GCD comprises an underlying rotation symmetry group of the configuration; and outputting the underlying rotation symmetry group of the configuration.