Coarse-Grained Parallel Algorithms for Multi-Dimensional Wavelet Transforms

This paper presents parallel algorithms for computing multi-dimensional wavelet transforms on both shared memory and distributed memory machines. Traditional data partitioning methods for n-dimensional Discrete Wavelet Transforms (DWTs) call for data redistribution once a one dimensional wavelet transform is computed along each dimension. To avoid the data communication inherent in this redistribution, two new partitioning methods called CRBP (Communication Reduced Block Partitioning) and CRLP (Communication Reduced Layer Partitioning) are proposed. The efficiency of the algorithms is compared through several examples implemented on a cluster of SGI workstations. Two kinds of parallel approaches are used to compute multi-dimensional wavelet transforms on shared memory machines: homogeneous parallelism, and heterogeneous parallelism. Homogeneous parallelism uses traditional data partitioning while heterogeneous parallelism uses the CRBP approach. The effectiveness of these approaches is demonstrated through several examples implemented on an SGI Power Challenge. The paper discusses the effectiveness of each of the approaches on the two kinds of architectures.