Face detection with Viola-Jones/Haar-like features

Haar-like features are very useful image features used in object detection. They were introduced in the very first real-time face detector by Viola and Jones. Using integral images, Haar-like features of any size (scale) can be efficiently computed in constant time. The computation speed is the key advantage of a Haar-like feature over most other features. Using the Viola-Jones face detection algorithm, faces can be detected in an image using these Haar-like features. Each Haar-like feature acts as just a weak classifier, and hence a huge number of these features are required to detect a face with good accuracy. Therefore, a large number of features are computed for all possible locations and sizes of each Haar-like kernel, using the integral images. Then, an AdaBoost ensemble classifier is used to select important features from...