Analytic Design of Uniform Circular Filter Banks

Abstract

This work proposes an analytic design method for a particular class of 2D filter banks, with circular shape in the frequency plane and a maximally-flat characteristic. The circular filters comprising the filter bank result starting from a zerophase prototype by applying specific frequency mappings; they are efficient, of relatively low order and good selectivity. Their transfer functions can be expressed in a closed form and depend explicitly on a parameter given by specified number of filters, e.g. in the case of an uniform circular filter bank. A design example is provided for imposed specification and the designed filter bank is tested in filtering a given texture image.