code: def get_frame(self):
      if self.valid:
          _, frame = self.cap.read()
          frame = cv2.flip(frame, 1)
          # cv2.putText(frame, str(self.cap.get(cv2.CAP_PROP_FRAME_WIDTH)),
          #           (65,220), cv2.FONT_HERSHEY_PLAIN, 2, (0,256,256))
      else:
          frame = np.ones((480, 640, 3), dtype=np.uint8)
          col = (0, 256, 256)
          cv2.putText(
              frame,
              "(Error: Camera not accessible)",
              (65, 220),
              cv2.FONT_HERSHEY_PLAIN,
              2,
              col,
          )
      return frame
  
file_path: heart-rate-measurement-camera/webcam.py
imports: import cv2
  import numpy
  import time
label_desc: Use image node_id 3 for calling the Webcam obj's underlying member method code with example usage: obj.get_frame() and returns: frame