code: def find_faces(self, image, draw_box=False):
          
          frame_gray = cv2.cvtColor(image, cv2.COLOR_RGB2GRAY)
          faces = self.cascade.detectMultiScale(
              frame_gray,
              scaleFactor=1.3,
              minNeighbors=5,
              minSize=(50, 50),
              flags=0)
  
          if draw_box:
              for x, y, w, h in faces:
                  cv2.rectangle(image, (x, y),
                                (x + w, y + h), (0, 255, 0), 2)
          return faces
docs: Uses a haarcascade to detect faces inside an image.
  
          Args:
              image: The image.
              draw_box: If True, the image will be marked with a rectangle.
  
          Return:
              The faces as returned by OpenCV's detectMultiScale method for
              cascades.