Computation of two-dimensional complex cepstrum

A technique based on fitting splines to the phase derivative curve is presented for the efficient and reliable computation of the two-dimensional complex cepstrum. The technique is an adaptive numerical integration scheme and makes use of several computational strategies within the Tribolet´s phase unwrapping algorithm. An application of the complex cepstrum in testing the stability of two-dimensional recursive digital filters is considered. Susceptibility of the computation of complex cepstrum to slight changes in the coefficients of a two-dimensional array is studied. Several examples of stable and unstable two-dimensional quarter-plane and non-symmetric half-plane recursive digital filters are presented.