Building Computer Vision Projects with OpenCV 4 and C++

Introduction to face detection and face recognition

Face recognition is the process of putting a label to a known face. Just like humans learn to recognize their family, friends, and celebrities just by seeing their face, there are many techniques for recognize a face in computer vision.

These generally involve four main steps, defined as follows:

1. Face detection: This is the process of locating a face region in an image (the large rectangle near the center of the following screenshot). This step does not care who the person is, just that it is a human face.
2. Face preprocessing: This is the process of adjusting the face image to look clearer and similar to other faces (a small grayscale face in the top center of the following screenshot). ...