code: def binarize_img(img):
      if len(img.shape) == 3 and img.shape[2] == 3:
          gray = cv2.cvtColor(
              img, cv2.COLOR_BGR2GRAY
          )  # conversion to grayscale image
          # use cv2 threshold binarization
          _, gray = cv2.threshold(
              gray, 0, 255, cv2.THRESH_BINARY + cv2.THRESH_OTSU
          )
          img = cv2.cvtColor(gray, cv2.COLOR_GRAY2BGR)
      return img
  
imports: import logging
  import os
  import imghdr
  import cv2
  import random
  import numpy
  import paddle
  import importlib.util
  import sys
  import subprocess
label_desc: Use image node_id 5 for calling a global function with example usage: binarize_img(img) and returns: img