Patent ID: 7411592

Claim:
A method for generating object perimeter information, comprising: determining a polar representation of the perimeter of an object to define polar perimeter information, including: rendering a depiction of the object from a vantage point of a light source, wherein the depiction of the object includes a plurality of object elements, and wherein a subset of the object elements forms the perimeter of the object; and ascertaining polar coordinates defining respective positions of the object elements that form the perimeter of the object by: identifying a sample object element; determining a polar angle value associated with a position of the sample object element within the depiction of the object; determining a polar radius value associated with the position of the sample object element within the depiction of the object; comparing the determined polar radius value with a previously stored polar perimeter radius value associated with the determined polar angle value; replacing the previously stored polar perimeter radius value with the determined polar radius value if the determined polar radius value is greater than the previously stored polar perimeter radius value; and successively repeating the operations of identifying through replacing for additional sample elements within the depiction; and storing the ascertained polar coordinates.