Hands-On Robotics Programming with C++

Basic working of the Viola-Jones algorithm

So, put simply, the Viola-Jones algorithm used Haar features to detect a face. Haar generally consists of two main features: edge features and line features. We will first understand these two features and then we will see how these features are used to detect faces:

• Edge features: This is generally used to detect edges. The edge feature consists of white and black pixels. Edge features can be further categorized into horizontal edge features and vertical edge features. In the following diagram, we can see the vertical edge feature on the left block and the horizontal edge feature on the right block:

• Line features: This is generally used to detect lines. In line features, a white pixel is sandwiched ...