Phase-based methods for Fourier shape matching

Interest in the problem of shape matching has been recently reignited by the huge proliferation of images on the Internet, particularly huge computer databases containing thousands or millions of images. Although many typical image database algorithms rely on a variety of shading, texture, and colour attributes, there are significant opportunities for the use of shape as a discriminator, particularly for binary or high-contrast images. Fourier shape descriptors have been studied extensively for shape comparison, however the descriptor phases have been mostly neglected - either ignored entirely or treated simplistically. This paper formalizes the use of phase in shape matching, and derives shape discriminators, applicable to both simple and complex shapes.