In this chapter, we discussed Haar cascades and integral images. We understood how the face detection pipeline is built. We learnt how to detect and track faces in a live video stream. We discussed how to use the face detection pipeline to detect various body parts like eyes, ears, nose, and mouth. We learnt how to overlay masks on top on the input image using the results of body parts detection. We used the principles of shape analysis to detect the pupils.

In the next chapter, we are going to discuss feature detection and how it can be used to understand the image content.