WPFBT Wavelet Packet FilterBank Tree
Usage: c=wpfbt(f,wt);
[c,info]=wpfbt(...);
Input parameters:
f : Input data.
wt : Wavelet Filterbank tree definition.
Output parameters:
c : Coefficients stored in a cell-array.
info : Transform parameters struct.
c=WPFBT(f,wt) returns wavelet packet coefficients c obtained by
applying a wavelet filterbank tree defined by wt to the input data
f.
[c,info]=WPFBT(f,wt) additionally returns struct. info containing
transform parameters. It can be conviniently used for the inverse
transform IWPFBT e.g. fhat = iWPFBT(c,info). It is also required
by the PLOTWAVELETS function.
In contrast to WFBT, the cell array c contain every intermediate
output of each node in the tree. c{jj} are ordered according to
nodes taken in the breadth-first order.
If f is row/column vector, the coefficient vectors c{jj} are
columns. If f is a matrix, the transformation is applied to each of
column of the matrix.
Scaling of intermediate outputs:
--------------------------------
The following flags control scaling of intermediate outputs and
therefore the energy relations between coefficient subbands. An
intermediate output is an output of a node which is further used as an
input to a descendant node.
'intsqrt'
Each intermediate output is scaled by 1/sqrt(2).
If the filterbank in each node is orthonormal, the overall
undecimated transform is a tight frame.
This is the default.
'intnoscale'
No scaling of intermediate results is used. This is
necessaty for the WPBEST function to correctly work with
the cost measures.
'intscale'
Each intermediate output is scaled by 1/2.
If 'intnoscale' is used, 'intscale' must be used in IWPFBT (and vice
versa) in order to obtain a perfect reconstruction.
Please see help for WFBT description of possible formats of wt and
of the additional flags defining boundary handling.
Examples:
---------
A simple example of calling the WPFBT function using the "full
decomposition" wavelet tree:
f = gspi;
J = 6;
[c,info] = wpfbt(f,{'sym10',J,'full'});
plotwavelets(c,info,44100,'dynrange',90);
Url: http://ltfat.github.io/doc/wavelets/wpfbt.html
See also: wfbt, iwpfbt, wfbtinit, plotwavelets, wpbest.
Package: ltfat