Wavelet Toolbox

Example 4: Building a Wavelet Tree Object (EDWTTREE)

This example creates a new class of objects: EDWTTREE.

We define an -DWT tree class starting from the class DTREE and overloading the methods merge, plot, recons, and split.

For more information on the -DWT, see the section e-Decimated DWT.

The plot method shows how to add Node Labels, Node Actions, and Tree Actions.

You can have a look at the example in the ex1_edwt M-file located in the toolbox/wavelet/wavedemo directory. This program can be used directly, but it is also useful to learn how to build new object-oriented programming functions.

The definition of the new class is described below.

Class EDWTTREE (parent class: DTREE)

Fields

dtree	Parent object
dwtMode	DWT extension mode
wavInfo	Structure (wavelet information)

Fields Description

wavInfo

wavName	- Wavelet Name
Lo_D	- Low Decomposition filter
Hi_D	- High Decomposition filter
Lo_R	- Low Reconstruction filter
Hi_R	- High Reconstruction filter

Methods

edwttree	Constructor for the class EDWTTREE.
merge	Merge (recompose) the data of a node.
plot	Plot EDWTTREE object.
recons	Reconstruct node coefficients.
split	Split (decompose) the data of a terminal node.

Running This Example

The following figure is obtained using the example ex1_edwt, selecting the De-noise option in the Tree Action menu and clicking the node 0.

The approximations are labeled in yellow and the details are labeled in red. The last nodes cannot be split.

The title of the figure contains the DWT extension mode used ('sym' in the present example) and the name of the de-noising method.

Example 3: Building a Wavelet Tree Object (WVTREE)

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