Computer Vision Demonstration Website

Electronics and Computer Science
University of Southampton

Standard and Hysteresis Thresholding

Two types of thresholding are shown here. The standard mode just uses the lower threshold value to perform the threshold, whilst hysteresis uses both threshold values.

How it works

The standard mode looks at the original image and turns any pixels lower than the threshold to black, and any values above it to white.

The hysteresis mode uses a hysteresis loop to provide a more connected result. Any pixel above the upper threshold is turned white. The surround pixels are then searched recursively. If the values are greater than the lower threshold they are also turned white. The result is that there are many fewer specks of white in the resulting image.

Code

Image processing classes:

• hystThresh.java
• The standard thresholding is provided by a function within the framework (thresholding.java)

Demo framework:

• thresholding.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