Fast design of 2-D linear-phase complex FIR digital filters by analytical least squares method

Abstract

Two-dimensional full-plane and half-plane filters are more general, and much better frequency responses can be obtained than the quarter-plane filters. In this correspondence, the analytical least squares method is generalized and extended for designing 2-D full-plane and half-plane linear phase complex FIR digital filters. The 2-D filter's coefficients can be effectively determined by use of a closed-form transformation matrix and some simple element functions. The unique advantage of this technique is that it is very fast without employing iterative optimization procedures and matrix inversions. Design examples are presented to illustrate the simplicity and efficiency of the proposed method.