DTWFBINIT - Dual-Tree Wavelet Filterbank Initialization

Usage

dualwt=dtwfbinit(dualwtdef);

Input parameters

Output parameters

Description

dtwfinit() (a call without aguments) creates an empty structure. It has the same fields as the struct. returned from wfbtinit plus a field to hold nodes from the second tree:

.nodes Filterbank nodes of the first tree

.dualnodes Filterbank nodes of the second tree

.children Indexes of children nodes

.parents Indexes of a parent node

.forder Frequency ordering of the resultant frequency bands.

dtwfinit({dualw,J,flag}) creates a structure representing a dual-tree wavelet filterbank of depth J, using dual-tree wavelet filters specified by dualw. The shape of the tree is controlled by flag. Please see help on dtwfb or dtwfbreal for description of the parameters.

[dualwt,info]=dtwfinit(...) additionally returns info struct which provides some information about the computed window:

info.tight

True if the overall tree construct a tight frame.

info.dw

A structure containing basic dual-tree filters as returned from fwtinit(dualwtdef,'wfiltdt_').

Additional optional flags

'freq',`'nat'`

Frequency or natural ordering of the resulting coefficient subbands. Default ordering is 'freq'.