Face and object recognition
Face recognition refers to identifying the person in a given image. This is not the same as face detection, where you simply identify the location of a face in the given image.
If you want to build a practical biometric system that can recognize the person in front of the camera, you first need to run a face detector to identify the location of the face, and then run a separate face recognizer to identify who the person is. There is an OpenCV module called face that deals with face recognition.
As we discussed earlier, computer vision tries to model algorithms based on how humans perceive visual data. So, it would be helpful to find salient regions and objects in the images that can help with different applications such as object recognition, object detection and tracking, and so on. There is a module called saliency that's designed for this purpose. It provides algorithms that can detect salient regions in static images and videos.