Tutorials

• Visualizing Wavelets, Wavelet Packets, and Wavelet Filters
  

  Obtain the filters, wavelet, or wavelet packets corresponding to a particular wavelet family.

• Continuous Wavelet Analysis
  

  Perform time-frequency analysis with the continuous wavelet transform.

• Discrete Wavelet Analysis
  

  Analyze and denoise signals and images using discrete wavelet transform techniques.

• Lifting
  

  Use lifting to design wavelet filters while performing the discrete wavelet transform.

• Critically Sampled Wavelet Packet Analysis
  

  Obtain the wavelet packet transform of a 1-D signal and a 2-D image.

• Matching Pursuit
  

  Create matching pursuit dictionaries and perform matching pursuit on 1-D signals.

About Wavelets

• What is a Wavelet?
  

  Learn general information about wavelets and how to detect a signal discontinuity.

• Wavelet Families and Properties
  

  View wavelet families and the type of analysis each wavelet supports.

• Continuous and Discrete Wavelet Transforms
  

  Decide whether to use a discrete or continuous wavelet transform.

Featured Examples

Denoise a Signal with the Wavelet Signal Denoiser

Use the Wavelet Signal Denoiser app to denoise a real-valued 1-D signal. You can create and compare multiple versions of a denoised signal with the app and export the desired denoised signal to your MATLAB® workspace. To reproduce the denoised signal in your workspace, or to apply the same denoising parameters to other data, you can generate and edit a MATLAB script. This example illustrates one possible workflow.

Open Live Script

Time-Frequency Analysis with the Continuous Wavelet Transform

Use the continuous wavelet transform (CWT) to analyze signals jointly in time and frequency. The example discusses the localization of transients where the CWT outperforms the short-time Fourier transform (STFT). The example also shows how to synthesize time-frequency localized signal approximations using the inverse CWT.

Open Script

Videos

Understanding Wavelets, Part 1: What Are Wavelets
Explore the fundamental concepts of wavelet transforms in this introductory MATLAB Tech Talk. This video covers what wavelets are and how you can use them to explore your data in MATLAB. The video focuses on two important wavelet transform concepts: scaling and shifting. The concepts can be applied to 2-D data such as images.

Understanding Wavelets, Part 2: Types of Wavelet Transforms
Explore the workings of wavelet transforms in detail. You will learn more about the continuous wavelet transforms and the discrete wavelet transform. You will also learn important applications of using wavelet transforms with MATLAB.

Understand Wavelets, Part 3: An Example Application of the Discrete Wavelet Transform
Learn how to use to wavelets to denoise a signal while preserving its sharp features in this MATLAB Tech Talk. This video outlines the steps involved in denoising a signal with the discrete wavelet transform using MATLAB. Learn how this denoising technique compares with other denoising techniques.

Understanding Wavelets, Part 4: An Example Application of the Continuous Wavelet Transform
Explore a practical application of using continuous wavelet transforms in this MATLAB Tech Talk. Get an overview of how to use MATLAB to obtain a sharper time-frequency analysis of a signal with the continuous wavelet transform. This video uses an example seismic signal to highlight the frequency localization capabilities of the continuous wavelet transform.