Spatial recursive filter design via rational Chebyshev approximation

The computer implementation of a numerical algorithm for obtaining rational approximations is discussed. This method offers the promise of a comprehensive solution to the problems of two-dimensional recursive digital filter design. Combination of this technique with an easily implemented stability test avoids current stability problems in present methods and places no restrictions as to type on filters that may be designed. Both one- and two-dimensional filters may be designed with this technique.