FILTERBANKDUAL Dual filters
Usage: gd=filterbankdual(g,a,L);
gd=filterbankdual(g,a);
FILTERBANKDUAL(g,a,L) computes the canonical dual filters of g for a
channel subsampling rate of a (hop-size) and system length L.
L must be compatible with subsampling rate a as
L==filterbanklength(L,a). This will create a dual frame valid for
signals of length L.
filterabankrealdual(g,a) does the same, but the filters must be FIR
filters, as the transform length is unspecified. L will be set to
next suitable length equal or bigger than the longest impulse response
such that L=filterbanklength(gl_longest,a).
The input and output format of the filters g are described in the
help of FILTERBANK.
In addition, the funtion recognizes a 'forcepainless' flag which
forces treating the filterbank g and a as a painless case
filterbank.
To actually invert the output of a filterbank, use the dual filters
together with the IFILTERBANK function.
REMARK: In general, perfect reconstruction can be obtained for signals
of length L. In some cases, using dual system calculated for shorter
L might work but check the reconstruction error.
Url: http://ltfat.github.io/doc/filterbank/filterbankdual.html
See also: filterbank, ufilterbank, ifilterbank.
Package: ltfat