Design of 2-D separable-denominator recursive digital filters

This paper presents a technique for finding the coefficients of a two-dimensional (2-D) recursive digital filter having a separable denominator which gives the best approximation, in the least squares sense, to a desired 2-D impulse response over a finite interval. All the coefficients in the filter are found by iteratively solving linear equations. Since the resulting filter has a separable denominator, it is easy to check the stability and the implementation is simpler. Two examples are given to illustrate the utility of the proposed technique.