Using OpenCV to perform face detection

With cv2.CascadeClassifier, it makes little difference whether we perform face detection on a still image or a video feed. The latter is just a sequential version of the former: face detection on a video is simply face detection applied to each frame. Naturally, with more advanced techniques, it would be possible to track a detected face continuously across multiple frames and determine that the face is the same one in each frame. However, it is good to know that a basic sequential approach also works.

Let's go ahead and detect some faces.

Performing face detection on a still image

The first and most basic way to perform face detection is to load an image and detect faces in it...