2-D direct form, recursive filter design with magnitude and phase specifications

This paper presents an extension of the spectral factorization based optimization method to approximate both magnitude and phase specifications for 2-D, recursive, direct-form, nonsymmetric half-plane filters. Examples are presented of filters approximating ideal linear phase lowpass and fan filters as well as causal (in the nonsymmetric half-plane sense) Wiener filters which have non-linear phase characteristics.