A mixed Butterworth/Daubechies wavelet analysis/synthesis system

This paper discusses the close relationship between the FIR Daubechies wavelet filters and the IIR Butterworth wavelet filters. The frequency responses of both types of filters are first compared. An “almost equivalent” Daubechies/Butterworth pair is then identified. To demonstrate the “equivalence” of these two filters, a wavelet-based filter bank using a combination of Daubechies/Butterworth filters is proposed. This relationship is used to implement a fully causal, more efficient filter bank. An example to verify the performance of the proposed hybrid system is given