WFBTINIT Initialize Filterbank Tree
Usage: wt = wfbtinit(wtdef);
Input parameters:
wtdef : Filterbank tree definition.
Output parameters:
wt : Structure describing the filter tree.
WFBTINIT({w,J,flag}) creates a filterbank tree of depth J. The
parameter w defines a basic wavelet filterbank. For all possible
formats see FWT. The following optional flags (still inside of the
cell-array) are recognized:
'dwt','full','doubleband','quadband','octaband'
Type of the tree to be created.
WFBTINIT({w,J,flag,'mod',mod}) creates a filterbank tree as before,
but modified according to the value of mod.
Recognized options:
'powshiftable'
Changes subsampling factors of the root to 1. This results in redundant
near-shift invariant representation.
The returned structure wt has the following fields:
.nodes
Cell-array of structures obtained from FWTINIT. Each element
define a basic wavelet filterbank.
.children
Indexes of children nodes
.parents
Indexes of a parent node
.forder
Frequency ordering of the resultant frequency bands.
The structure together with functions from the wfbtmanip
subdirectory acts as an abstract data structure tree.
Regular WFBTINIT flags:
'freq','nat'
Frequency or natural ordering of the coefficient subbands. The direct
usage of the wavelet tree ('nat' option) does not produce coefficient
subbans ordered according to the frequency. To achieve that, some
filter shuffling has to be done ('freq' option).
Url: http://ltfat.github.io/doc/wavelets/wfbtinit.html
See also: wfbtput, wfbtremove.
Package: ltfat