Some results on two-dimensional pseudoquadrature mirror filters

One-dimensional (1-D) pseudoquadrature mirror filters (PQMF\´s) have been introduced as a generalization of quadrature mirror, filter (QMF) concepts. Use of such filters allows one to split directly the spectrum of an input signal into equally spaced subbands which can be decimated by , then interpolated and recombined to reproduce the original signal. In this paper, a detailed derivation of conditions specifying 2-D PQMF design constraints for a distortion-free (i.e., aliasing and amplitude distortions) reconstruction of the original signal are obtained. Potential applications for such filters include efficient subband coding of digital pictures.