A Python Computer Vision program that uses the cv2 library to accept a photo as input, attempt to detect the presence of a face and if found, draw a rectangle around it. The information that the program uses to detect faces in an image - the training data if you will - is found in an xml file that can be found in the repo above. The model is trained with a grayscale image and tested with a color image, this is done to test accuracy as it is not tested with the same data it was trained with.
How to carry out facial detection with the cv2 Computer Vision library