Two dimensional filters have seen substantial development effort due to their importance and large applicability across several domains. In the 2-D case the situation is quite different from 1-D case, because the multi-dimensional polynomials can't be factored in generally. This means that an arbitrary transfer function can generally not be manipulated into a form required by a particular implementation. The input-output relationship of a 2-D IIR filter obeys a constant-coefficient linear partial difference equation from which the value of an output sample can be computed using the input samples and previously computed output samples. Because the values of the output samples are fed back, the 2-D filter, like its 1-D counterpart, can be unstable.  [More Information]
There are no implementations available for this algorithm yet.