import numpy as np
import cv2

faceClassifier = cv2.CascadeClassifier("haarcascade_frontalface_default.xml")
img = cv2.imread("detection2Learn.jpg")
gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
face_cascade = cv2.CascadeClassifier(cv2.data.haarcascades + 'haarcascade_frontalface_default.xml')
faces = face_cascade.detectMultiScale(gray, 1.1, 2)

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