face_detection.py

    '''
    Face Detection
    -> Using method used by Viola and jones (real time object detection)
    -> We will use lot of images with positive faces and negative faces and will train the cascade file to detect the faces
    -> In Open CV we dont have to actually do this we can use trained cascade file to detect things
    '''
    import cv2
    faceCascade = cv2.CascadeClassifier("Resources/haarcascade_frontalface_default.xml")
    img = cv2.imread("Resources/lena.png")
    imgGray = cv2.cvtColor(img,cv2.COLOR_BGR2GRAY)

    faces = faceCascade.detectMultiScale(imgGray,1.1,4)

    for (x,y,w,h) in faces:
        cv2.rectangle(img,(x,y),(x+w,y+h),(255,0,0),2)

    cv2.imshow("Result",img)
    cv2.waitKey(0)