code: def ColorNormalize(batch_img):
      mean = 0.413621
      std = 0.1700239
      batch_img = (batch_img - mean) / std
      return batch_img
  
imports: import random
  import cv2
  import numpy
label_desc: Use image node_id 4 for calling a global function with example usage: ColorNormalize(batch_img) and returns: batch_img