Filter bank tree and M-band wavelet packet algorithms in audio signal processing

This article investigates M-band wavelet packets and a generalized framework for the design and efficient utilization of multirate filter bank trees (FBTs). While the increased flexibility of M-band wavelet over the standard two-band wavelet packets is desirable in many signal processing applications, the possibilities in time-frequency design using arbitrary filter bank cascades are even greater. We show how to construct FBTs for arbitrary given tree-like splits of the time-frequency plane. Furthermore, we give an explicit construction for efficient simultaneous subband and spectral analysis in the general FRT case. Results from audio signal processing applications show that the proposed methods in many cases yield better results than those using standard wavelet packets.