Wavelet Toolbox

Getting Started

Preface

About the Authors

Notes by Yves Meyer

Notes by Ingrid Daubechies

Acknowledgements

What Is the Wavelet Toolbox?

Using This Guide

Caution

For More Background

Installing the Wavelet Toolbox

System Recommendations

Platform-Specific Details

Typographical Conventions

Related Products List

Wavelets: A New Tool for Signal Analysis

Wavelet Applications

Scale aspects

Time aspects

Wavelet Decomposition as a Whole

Fourier Analysis

Short-Time Fourier Analysis

Wavelet Analysis

What Can Wavelet Analysis Do?

What Is Wavelet Analysis?

Number of Dimensions

The Continuous Wavelet Transform

Scaling

Shifting

Five Easy Steps to a Continuous Wavelet Transform

Scale and Frequency

The Scale of Nature

What's Continuous About the Continuous Wavelet Transform?

The Discrete Wavelet Transform

One-Stage Filtering: Approximations and Details

Multiple-Level Decomposition

Wavelet Reconstruction

Reconstruction Filters

Reconstructing Approximations and Details

Relationship of Filters to Wavelet Shapes

Multistep Decomposition and Reconstruction

Wavelet Packet Analysis

History of Wavelets

An Introduction to the Wavelet Families

Haar

Daubechies

Biorthogonal

Coiflets

Symlets

Morlet

Mexican Hat

Meyer

Other Real Wavelets

Complex Wavelets

Using the Wavelet Toolbox

Using Wavelets

One-Dimensional Continuous Wavelet Analysis

Continuous Analysis Using the Command Line

Continuous Analysis Using the Graphical Interface

Importing and Exporting Information from the Graphical Interface

One-Dimensional Complex Continuous Wavelet Analysis

Complex Continuous Analysis Using the Command Line

Complex Continuous Analysis Using the Graphical Interface

Importing and Exporting Information from the Graphical Interface

One-Dimensional Discrete Wavelet Analysis

One-Dimensional Analysis Using the Command Line

One-Dimensional Analysis Using the Graphical Interface

Importing and Exporting Information from the Graphical Interface

Two-Dimensional Discrete Wavelet Analysis

Two-Dimensional Analysis Using the Command Line

Two-Dimensional Analysis Using the Graphical Interface

Importing and Exporting Information from the Graphical Interface

Wavelets: Working with Images

Understanding Images in MATLAB

Indexed Images

Wavelet Decomposition of Indexed Images

Other Images

Image Conversion

One-Dimensional Discrete Stationary Wavelet Analysis

One-Dimensional Analysis Using the Command Line

One-Dimensional Analysis for De-noising Using the Graphical Interface

Importing and Exporting Information from the Graphical Interface

Two-Dimensional Discrete Stationary Wavelet Analysis

Two-Dimensional Analysis Using the Command Line

Two-Dimensional Analysis for De-noising Using the Graphical Interface

Importing and Exporting Information from the Graphical Interface

One-Dimensional Wavelet Regression Estimation

One-Dimensional Estimation Using the GUI for Equally Spaced Observations (Fixed Design)

One-Dimensional Estimation Using the GUI for Randomly Spaced Observations (Stochastic Design)

Importing and Exporting Information from the Graphical Interface

One-Dimensional Wavelet Density Estimation

One-Dimensional Estimation Using the Graphical Interface

Importing and Exporting Information from the Graphical Interface

One-Dimensional Variance Adaptive Thresholding of Wavelet Coefficients

One-Dimensional Local Thresholding for De-noising Using the Graphical Interface

Importing and Exporting Information from the Graphical Interface

One-Dimensional Selection of Wavelet Coefficients Using the Graphical Interface

Two-Dimensional Selection of Wavelet Coefficients Using the Graphical Interface

One-Dimensional Extension

One-Dimensional Extension Using the Command Line

One-Dimensional Extension Using the Graphical Interface

Importing and Exporting Information from the Graphical Interface

Two-Dimensional Extension

Two-Dimensional Extension Using the Command Line

Two-Dimensional Extension Using the Graphical Interface

Importing and Exporting Information from the Graphical Interface

Wavelet Applications

Detecting Discontinuities and Breakdown Points I

Discussion

Detecting Discontinuities and Breakdown Points II

Discussion

Detecting Long-Term Evolution

Discussion

Detecting Self-Similarity

Wavelet Coefficients and Self-Similarity

Discussion

Identifying Pure Frequencies

Discussion

Suppressing Signals

Discussion

De-Noising Signals

Discussion

De-noising Images

Discussion

Compressing Images

Discussion

Fast Multiplication of Large Matrices

Wavelets in Action: Examples and Case Studies

Illustrated Examples

Advice to the Reader

Example 1: A Sum of Sines

Example 2: A Frequency Breakdown

Example 3: Uniform White Noise

Example 4: Colored AR(3) Noise

Example 5: Polynomial + White Noise

Example 6: A Step Signal

Example 7: Two Proximal Discontinuities

Example 8: A Second-Derivative Discontinuity

Example 9: A Ramp + White Noise

Example 10: A Ramp + Colored Noise

Example 11: A Sine + White Noise

Example 12: A Triangle + A Sine

Example 13: A Triangle + A Sine + Noise

Example 14: A Real Electricity Consumption Signal

Case Study: An Electrical Signal

Data and the External Information

Analysis of the Midday Period

Analysis of the End of the Night Period

Suggestions for Further Analysis

Using Wavelet Packets

About Wavelet Packet Analysis

One-Dimensional Wavelet Packet Analysis

Compressing a Signal Using Wavelet Packets

De-Noising a Signal Using Wavelet Packets

Two-Dimensional Wavelet Packet Analysis

Compressing an Image Using Wavelet Packets

Importing and Exporting from Graphical Tools

Saving Information to Disk

Loading Information into the Graphical Tools

Advanced Concepts

Mathematical Conventions

General Concepts

Wavelets: A New Tool for Signal Analysis

Wavelet Decomposition: A Hierarchical Organization

Finer and Coarser Resolutions

Wavelet Shapes

Wavelets and Associated Families

Wavelet Transforms: Continuous and Discrete

Local and Global Analysis

Synthesis: an Inverse Transform

Details and Approximations

The Fast Wavelet Transform (FWT) Algorithm

Filters Used to Calculate the DWT and IDWT

Algorithms

Why Does Such an Algorithm Exist?

One-Dimensional Wavelet Capabilities

Two-Dimensional Wavelet Capabilities

Dealing with Border Distortion

Signal Extensions: Zero-Padding, Symmetrization, and Smooth Padding

Discrete Stationary Wavelet Transform (SWT)

e-decimated DWT

How to Calculate the e-decimated DWT: SWT

Inverse Discrete Stationary Wavelet Transform (ISWT)

More about SWT

Frequently Asked Questions

Wavelet Families: Additional Discussion

Daubechies Wavelets: dbN

Symlet Wavelets: symN

Coiflet Wavelets: coifN

Biorthogonal Wavelet Pairs: biorNr.Nd

Meyer Wavelet: meyr

Battle-Lemarie Wavelets

Mexican Hat Wavelet: mexh

Morlet Wavelet: morl

Other Real Wavelets

Complex Wavelets

Summary of Wavelet Families and Associated Properties (Part 1)

Summary of Wavelet Families and Associated Properties (Part 2)

Wavelet Applications: More Detail

Suppressing Signals

Splitting Signal Components

Noise Processing

De-Noising

Data Compression

Function Estimation: Density and Regression

Available Methods for De-noising, Estimation and Compression Using GUI Tools

Wavelet Packets

From Wavelets to Wavelet Packets: Decomposing the Details

Wavelet Packets in Action: an Introduction

Building Wavelet Packets

Wavelet Packet Atoms

Organizing the Wavelet Packets

Choosing the Optimal Decomposition

Some Interesting Subtrees

Wavelet Packets 2-D Decomposition Structure

Wavelet Packets for Compression and De-Noising

References

Adding Your Own Wavelets

Preparing to Add a New Wavelet Family

Choose the Wavelet Family Full Name

Choose the Wavelet Family Short Name

Determine the Wavelet Type

Define the Orders of Wavelets Within the Given Family

Build a MAT-File or M-File

Define the Effective Support

Adding a New Wavelet Family

Example 1

Example 2

After Adding a New Wavelet Family

Reference

Reference

Functions by Category

allnodes

appcoef

appcoef2

bestlevt

besttree

biorfilt

biorwavf

centfrq

cgauwavf

cmorwavf

coifwavf

cwt

dbaux

dbwavf

ddencmp

depo2ind

detcoef

detcoef2

drawtree

dtree

dwt

dwt2

dwtmode

dyaddown

dyadup

entrupd

fbspwavf

gauswavf

get

idwt

idwt2

ind2depo

instdfft

intwave

isnode

istnode

iswt

iswt2

leaves

mexihat

meyer

meyeraux

morlet

nodeasc

nodedesc

nodejoin

nodepar

nodesplt

noleaves

nstdfft

ntnode

ntree

orthfilt

plot

qmf

rbiowavf

read

readtree

scal2frq

set

shanwavf

swt

   swt2  

symaux

symwavf

thselect

tnodes

treedpth

treeord

upcoef

upcoef2

upwlev

upwlev2

wavedec

wavedec2

wavedemo

wavefun

waveinfo

wavemenu

wavemngr

waverec

waverec2

wbmpen

wcodemat

wdcbm

wdcbm2

wden

wdencmp

wentropy

wextend

wfilters

wkeep

wmaxlev

wnoise

wnoisest

wp2wtree

wpbmpen

wpcoef

wpcutree

wpdec

wpdec2

wpdencmp

wpfun

wpjoin

wprcoef

wprec

wprec2

wpsplt

wpthcoef

wptree

wpviewcf

wrcoef

wrcoef2

wrev

write

wtbo

   wthcoef

wthcoef2

wthresh

wthrmngr

Discrete Wavelet 1-D options.

Discrete Stationary Wavelet 1-D options.

Discrete Wavelet 2-D options.

Discrete Stationary Wavelet 2-D options.

Discrete Wavelet Packet 1-D options.

Discrete Wavelet Packet 2-D options.

wtreemgr

wvarchg

GUI Reference

General Features

Color Coding

Connectedness of Plots

Using the Mouse

Controlling the Colormap

Controlling the Number of Colors

Controlling the Coloration Mode

Using Menus

Using the View Axes Button

Using the Interval Dependent Threshold Settings Tool

Continuous Wavelet Tool Features

Wavelet 1-D Tool Features

Tree Mode

More Display Options

Wavelet 2-D Tool Features

Wavelet Packet Tool Features (1-D and 2-D)

Node Action Functionality

Wavelet Display Tool

Wavelet Packet Display Tool

Object-Oriented Programming

Short Description of Objects in the Toolbox

Simple Use of Objects Through Four Examples

Example 1: plot and wpviewcf

Example 2: drawtree and readtree

Example 3: A Funny One

Example 4: Thresholding Wavelet Packets

Detailed Description of Objects in the Toolbox

WTBO object

NTREE object

DTREE object

WPTREE object

Advanced Use of Objects

Example 1: Building a Wavelet Tree Object (WTREE)

Example 2: Building a Right Wavelet Tree Object (RWVTREE)

Example 3: Building a Wavelet Tree Object (WVTREE)

Example 4: Building a Wavelet Tree Object (EDWTTREE)

New Features Detailed Description

New Graphical User Interface Tools

New Wavelets

New Functions

Enhancements

Compatibility with Earlier Versions


 Getting Started