[gu,au]=nonu2ufilterbank(g,a)
| g | Filters as a cell array of structs. |
| a | Subsampling factors. |
| gu | Filters as a cell array of structs. |
| au | Uniform subsampling factor. |
| pk | Numbers of copies of each filter. |
[gu,au]=nonu2ufilterbank(g,a) calculates uniform filterbank gu, au=lcm(a) which is identical to the (possibly non-uniform) filterbank g, a in terms of the equal output coefficients. Each filter g{k} is replaced by \(p(k)=au/a(k)\) advanced versions of itself such that \(z^{ma(k)}G_k(z)\) for \(m=0,\ldots,p-1\).
This allows using the factorisation algorithm when determining filterbank frame bounds in filterbankbounds and filterbankrealbounds and in the computation of the dual filterbank in filterbankdual and filterbankrealdual which do not work with non-uniform filterbanks.
One can change between the coefficient formats of gu, au and g, a using nonu2ucfmt and u2nonucfmt in the reverse direction.
S. Akkarakaran and P. Vaidyanathan. Nonuniform filter banks: New results and open problems. In P. M. C.K. Chui and L. Wuytack, editors, Studies in Computational Mathematics: Beyond Wavelets, volume 10, pages 259 --301. Elsevier B.V., 2003. [ DOI ]