Orthogonal realization of first-order allpass filters for two-dimensional signals

Abstract

Abstract. An orthogonal realization for two-dimensional first-order strictly-stable allpass transfer functions is presented. It cortsists of two shift (delay) elements (one for each dimension) and three two-input/two-output memoryless lossless cells (i.e., elementary orthogonal rotations). We establish a one-to-one correspondence between the parameters of our orthogonal realization and those of the corresponding transfer function. A brief discussion of finite precision effects on our realization and a comparison with previous realizations are also included.