from imutils import face_utils
import numpy as np
import argparse
import imutils
import dlib
import cv2
import time
import math
from imutils.video import VideoStream
def rass(x1,y1,x2,y2):
      return math.sqrt((x2-x1)**2+(y2-y1)**2)
detector = dlib.get_frontal_face_detector()
predictor = dlib.shape_predictor('shape_predictor_68_face_landmarks.dat')
vs = VideoStream().start()
time.sleep(2.0)
while True:
      frame = vs.read()
      frame = imutils.resize(frame, width=500)
      gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
      rects = detector(gray, 0)
      for (i, rect) in enumerate(rects):
            shape = predictor(gray, rect)
            shape = face_utils.shape_to_np(shape)
            (x, y, w, h) = face_utils.rect_to_bb(rect)
            cv2.rectangle(frame, (x, y), (x + w, y + h), (0, 255, 0), 2)
            cv2.putText(frame, "Face #{}".format(i + 1), (x - 10, y - 10),
        cv2.FONT_HERSHEY_SIMPLEX, 0.5, (0, 255, 0), 2)
      cv2.imshow("Frame", frame)
      key = cv2.waitKey(1) & 0xFF
      if key == ord("q"):
            break
cv2.destroyAllWindows()
vs.stop()