Two-Channel Orthogonal Filter Banks

A program for the design of a lowpass (scaling) FIR filter for a orthogonal two-channel filter bank (wavelet system). The filter has a specified ripple size and a specified degree of flatness. The filters produced by this program achieve a trade-off between the classical Herrmann (Daubechies) filter and an equi-ripple solution. This permits a trade-off between frequency selectivity and the number of vanishing moments.

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• Example
   
• Documentation
   
• Download Matlab programs as a single tar file
   
• Matlab programs listed separately
   
  • fir_orthog.m - main program
  • choose.m - binomial coefficients
  • local_max.m - local maxima
  • oref.m - refinement of extremals
  • polydiff.m - polynomial differentiation
  • h2mag.m - magnitude response

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Please direct comments and questions to I. W. Selesnick (selesi@ece.rice.edu).

For more details see: M. Lang, I. Selesnick, J. E. Odegard, C. S. Burrus, Constrained FIR Filter Design for 2-band Filter Banks and Orthonormal Wavelets, Presented at the 6th IEEE DSP Workshop, Oct 1994, Also a Rice University ECE technical report. [4 pages, 58KB] Abstract.