ERROR SPECTRUM SHAPING IN 2-D RECURSIVE DIGITAL-FILTERS USING ERROR FEEDBACK WITH QUADRANT-SYMMETRICAL OR ANTISYMMETRIC COEFFICIENTS

This paper treats error spectrum shaping for two-dimensional recursive digital filters. A technique is developed to obtain the optimal error feedback coefficients that minimize the noise variance at the filter output. The error feedback coefficients are constrained to be quadrant -symmetric or antisymmetric in order to reduce the number of multiplic ations required to about one fourth. The optimal solution of the error feedback coefficients is characterized in closed form. A least-square s discrete space optimization procedure is then applied to obtain the optimal integer solution. This makes it possible to simplify the hardw are and to reduce the implementation cost. Finally, a numerical exampl e is given to demonstrate the effectiveness of the proposed technique. (C) 1998 Scripta Technica.