Theory and design of multidimensional two-channel near-perfect-reconstruction modulated filter banks

This article addresses the problem of designing two-channel near-perfect-reconstruction filter banks over multidimensional lattices. First, a cosine-modulated filter structure having arbitrary spatial shift and phase parameters is considered. The use of this structure leads to many possible two-channel multirate systems. The perfect reconstruction conditions are studied and appropriate choices for the parameters of the cosine-modulated structure are obtained. A simple but efficient unconstrained procedure for designing (possibly linear phase) near-perfect-reconstruction filter banks having good frequency responses (with arbitrary shapes) is proposed. A 2D design example is presented. The filter banks obtained can be used in transmultiplexers as well as in subband coders.