High-speed VLSI implementation of 2-d discrete wavelet transform

This paper presents a systematic high-speed VLSI implementation of the discrete wavelet transform (DWT) based on hardware-efficient parallel FIR filter structures. High-speed 2-D DWT with computation time as low as N-2/12 can be easily achieved for an N x N image with controlled increase of hardware cost. Compared with recently published 2-D DWT architectures with computation time of N-2/3 and 2N(2)/3, the proposed designs can also save a large amount of multipliers and/or storage elements. It can also be used to implement those 2-D DWT traditionally suitable for lifting or flipping-based designs, such as (9,7) and (6,10) DWT. The throughput rate can be improved by a factor of 4 by the proposed approach, but the hardware cost increases by a factor of around 3. Furthermore, the proposed designs have very simple control signals, regular structures and 100% hardware utilization for continuous images.