An Equilateral Polygon Approximation of Digital Contours

Abstract

In image processing, there are many cases where closed contours are desired to be equidistantly sampled along the contours in Euclidean meaning. For example, the P-type descriptor, a Fourier domain expression of contours, assumes that the contours to be processed are equilateral polygons, i.e. equidistantly sampled. So far many researchers, however, has approximated "the equidistance" by "the equal number of pixels apart". In this paper the effect of the equidistant resampling is clarified by some experiments.