Computer Vision Demonstration Website

Electronics and Computer Science
University of Southampton

Fourier Transform

The Fourier transform maps a signal into its component frequencies. It does not change the the orginal signal, only its representation. It is an extremely useful opeator used in many fields. The frequency based reprentation of the original image can be filtered, removing high or low frequency information, and then converted back into a standard image.

How it works

The equation for the Fourier transform, X, of a signal x, is given by the complex integral below:

The diagram below shows a Fourier transform of a pulse:

Code

Image processing classes:

• FFT.java
• InverseFFT.java
• ComplexNumber.java
• FreqFilter.java
• TwoDArray.java

Demo framework:

• fourierDemo.java

The pages were designed and developed for educational purposes only, to demonstrate how computer vision techniques work. They are designed for no other purpose and neither the authors nor their institutions accept any liability concerning use of these pages.

Links

Mark Nixon & Alberto Aguado, 2002, Feature Extraction & Image Processing, Newnes

ECS | Feature Extraction & Image Processing | © 2005 University of Southampton