A Shift, Scaling and Rotational Invariant Digital-figure Identification Based on Algebraic Equations

Abstract

A set of n points on the complex plane defines a polygon and determines an algebraic equation. If we normalize the coefficients of algebraic equations, two similar figures have an identical set of coefficients. By making use of this fact, figures that are mutually similar are identified. In this paper, we propose an identification method for figures which is invariant under shift, scaling and rotation. This method requires simpler computational processes than those required in methods proposed so far