Complexwavelet transforms with allpass #lters
A. Fernandes, Ivan Selesnick, Rutger L. C. van Spaendonck, C.S. Burrus · 2003
Complexdiscrete wavelet transforms (DWT) have signi#cant advantages over real wavelet transforms for certain signal processing problems. Two approaches to the implementation of complexwavelet transforms have been proposed earlier. Both approaches require discrete-time allpass systems having approximately linear-phase and (fractional) delay. This paper compares the results when di8erent allpass systems are used. In the earlier work, maximally 9at delay allpass systems were used. In this paper, it is shown that an allpass system designed according to the minimaxcriterion yields improvements for the complexDWT. ? 2003 Elsevier Science B.V. All rights reserved.