Techniques for determining the stability of two-dimensional recursive filters and their application to image restoration

General stability theorems and simple stability tests for two dimensional recursive digital filters were developed. The most general class of two dimensional filters was defined and several stability theorems for the class of filters are presented. The stability of any type of recursive filter can be determined from the stability of a first quadrant filter obtained by a suitable mapping of the original filter. A second theorem relates the stability of any type of two dimensional recursive filter to several simple conditions.