Abstract

A new 2-D image representation of the form with is introduced, and its use for image compression and classification is considered. The image is entirely represented by its invariant coefficients a_nk. The representation is a generalization of the circular harmonic decomposition, but the advantage is that any image is represented by a set of complex constants ank. The normalized coefficients are invariant under changes of scale or of orientation of the object represented by the coefficients. Experiments on grey scale imagery of aircraft show that images may be represented by a relatively small number of coefficients.

© 1989 Optical Society of America