1. A method for identifying an object appearing in an image, comprising: locating an object in the image; extracting a contour of the object from the image, the extracted contour having a plurality of points distributed along the contour, each point having a pair of orthogonal coordinate values associated with that point; generating a normalized contour from the extracted contour, the normalized contour having a determined number of normalized points distributed along the normalized contour, each normalized point having a pair of orthogonal coordinate values associated with that normalized point; determining, for each normalized point along the normalized contour, a summation invariant value for that normalized point; comparing, for at least one target object, each target object having a corresponding target contour, each target contour having the determined number of points distributed along that target contour, each determined point having a summation invariant value associated with that determined point, the summation invariant values for the determined number of normalized points along the normalized contour to the summation invariant values for the determined number of points along the target contour corresponding to that target object; determining, based on the comparison to the at least one target object, if the located object sufficiently matches any of the at least one target object; and identifying, if the located object is determined to sufficiently match any of the at least one target, the located object as the target object that is sufficiently matched.