Digit pipelined discrete wavelet transform

The paper describes a digit pipelined architecture for the 1D discrete wavelet transform, assuming a digit-serial model of computation. The use of simple operations and data movement makes it suitable for VLSI implementation and it can be easily mapped onto fine-grain custom VLSI and FPGA-based architectures. It achieves a factor of two speedup over a previous implementation of the same algorithm by virtue of digit pipelining made possible by the use of signed-digit arithmetic. In addition, the system can be clocked faster since it uses only nearest neighbor connections on a mesh, thus avoiding the signal propagation delays associated with long routing paths. An N-point DWT takes O(Nk) time and requires O(LJk) area, where L is the filter size, J is the number of octaves and k is the precision