Shape comparison using a rotational variation metric and applications thereof

摘要

A method for comparing geometric shapes to each other is disclosed. The method includes determination of a rotational variation metric. The shapes to be compared are scaled so that their lengths are equal and tangent vectors at corresponding locations along the geometric shapes are determined. The angle between each pair of corresponding tangent vectors for each of these locations is then plotted as a function of the length along the geometric shapes. The variation around the mean angle between the tangent vectors for the locations along the geometric shapes being compared is the rotational variation coefficient. This process defines a rotational variation metric which indicates how closely the two geometric shapes match. The rotational variation metric can be used in various geographic applications, including vehicle positioning, sign recognition, and evaluating geographic database accuracy.