The recursive pyramid algorithm for the discrete wavelet transform
Mohan Vishwanath · IEEE Transactions on Signal Processing · 1994
The recursive pyramid algorithm (RPA) is a reformulation of the classical pyramid algorithm (PA) for computing the discrete wavelet transform (DWT). The RPA computes the N-point DWT in real time (running DWT) using just L(log N/spl minus/1) words of storage, as compared with O(N) words required by the PA. L is the length of the wavelet filter. The RPA is combined with the short-length FIR filter algorithms to reduce the number of multiplications and additions.>