Open CV - Haar cascade face detection

Haar_cascade_face_detection.py

import cv2
import numpy as np
face_cascade = cv2.CascadeClassifier('haarcascade_frontalface_alt.xml')
cap = cv2.VideoCapture(0)
scaling_factor = 0.5
while True:
    ret, frame = cap.read()
    #frame = cv2.resize(frame, None, fx=scaling_factor, fy=scaling_factor,interpolation=cv2.INTER_AREA)
    gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
    face_rects = face_cascade.detectMultiScale(gray,1.3, 5)
    for (x,y,w,h) in face_rects:
        cv2.rectangle(frame, (x,y), (x+w,y+h), (0,255,0), 3)
    cv2.imshow('Face Detector', frame)
    c = cv2.waitKey(1)
    if c == 27:
        break
cap.release()
cv2.destroyAllWindows()