On the Phase of Least-asymmetric Scaling and Wavelet Filters

  • Published 1995


{ When using the discrete wavelet transform it is important that the lters at each scale are suitably shifted so that energy in the output sequence is appropriately positioned. We derive the form of the advance to apply to Daubechies' least-asymmetric scaling and wavelet lters at each scale, in order to obtain nearest to zero phase. At each scale the appropriate advance depends on whether half the length of each of the original quadrature mirror lters is even or odd. The departures from zero phase of the appropriately shifted wavelet lters are illustrated. The conditions under which the phase of appropriately shifted scaling and wavelet lters is continuous across octave bands (i.e., across scales) is investigated; the shifts derived here give rise to continuous phase functions.

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@inproceedings{INTRODUCTIONWhen1995OnTP, title={On the Phase of Least-asymmetric Scaling and Wavelet Filters}, author={I . INTRODUCTIONWhen}, year={1995} }