Efficient array architectures for multi-dimensional lifting-based discrete wavelet transforms

摘要

Efficient array architectures for multi-dimensional (m-D) discrete wavelet transform (DWT), e.g. m = 2,3, are presented, in which the lifting scheme of DWT is used to reduce efficiently hardware complexity. The parallelism of 2~m subbands transforms in lifting-based w-D DWT is explored, which increases efficiently the throughput rate of separable m-D DWT with fewer additional hardware overhead. The proposed architecture is composed of m2~(m-1) 1-D DWT modules working in parallel and pipelined, which is designed to process 2~m input samples per clock cycle, and generate 2~m subbands coefficients synchronously. The total time of achieving one level of decomposition for a 2-D image of size N~2 is approximately N~2/4 intra-clock cycles (ccs), and that for a 3-D image sequence of size MN~2 is approximately MN~2/8 ccs. Efficient line-based architecture frameworks for both 2D + t (spatial domain decomposition first, followed by temporal directional decomposition) and t + 2D (temporal directional decomposition first, followed by spatial domain decomposition) 3-D DWT are firstly proposed, as much as we know. Compared with the similar works reported in previous literature, the proposed architectures have good performance in terms of throughput rate and system output latency, and are good alternatives in tradeoff between throughput rate and hardware complexity. The proposed architectures are simple, regular, scalable and well suited for VLSI implementation.