Design of 2-D recursive filters with asymmetric half-plane lattice modelling

A method, based on 2-D asymmetric half-plane lattice parameters, for the design of two dimensional (2-D) recursive digital filters is presented. The design procedure calculates the lattice parameter factors from the prescribed frequency characteristics. The order of the design is controlled by an a priori error criterion, corresponding to the minimum mean squared error between two successive stages. The stability of the resulting filter is determined at each successive lattice stage from the computed 2D reflection factors. The capabilities of the proposed approach are demonstrated by the design of a fan filter and circularly symmetric lowpass filter. The computer time for their design is of the order of seconds for both filters