Novel Architecture for Lifting Discrete Wavelet Packet Transform With Arbitrary Tree Structure

Abstract

This brief presents a novel pipelined VLSI architecture for computing discrete wavelet packet transform (DWPT) with an arbitrary wavelet tree. Coefficients for different levels are computed in a series of stages. Each stage consists of a bypassed wavelet filter and circuit for reordering intermediate coefficients. The proposed lifting-based wavelet filter computes high- and low-pass coefficients in series. In order to accommodate the arbitrary tree structure, the filter either computes the coefficients or bypass the samples. The reordering of intermediate coefficients forms a subband required for next-level computation. The coefficients are computed in a serial manner and reordering of intermediate coefficients reduce not only the memory elements but also the circuit complexity. The proposed pipelined architecture reduces the requirement of memory elements by 50%. Furthermore, the hardware implementation results show that the area and power requirement are reduced by 33% and 20%, respectively.