import cv2
face_cascade = cv2.CascadeClassifier("haarcascade_frontalface_alt.xml")
cap  = cv2.VideoCapture(0)
while(True):
    
    ret,frame = cap.read()
    #gray_frame = cv2.cvtColor(frame,cv2.COLOR_BGR2GRAY)
    if(ret==False):
        continue
    faces  = face_cascade.detectMultiScale(frame,1.3,5)
    for (x,y,w,h) in faces:
        cv2.rectangle(frame,(x,y),(x+w,y+h),(255,0,0),1)
    cv2.imshow("video frame",frame)
    key_pressed = cv2.waitKey(1)&0xFF
    if(key_pressed == ord('q')):
        break  
cap.release()
cv2.destroyAllWindows()