code: def color_normalization(image, mean, stddev):
      """
      Perform color normalization on the image with the given mean and stddev.
      Args:
          image (array): image to perform color normalization.
          mean (float): mean value to subtract.
          stddev (float): stddev to devide.
      """
      # Input image should in format of CHW
      assert (
          len(mean) == image.shape[0]
      ), "channel mean not computed properly"
      assert (
          len(stddev) == image.shape[0]
      ), "channel stddev not computed properly"
      for idx in range(image.shape[0]):
          image[idx] = image[idx] - mean[idx]
          image[idx] = image[idx] / stddev[idx]
      return image
  
imports: import math
  import numpy
  import cv2
label_desc: Use image node_id 11 for calling a global function with example usage: color_normalization(image, mean, stddev) and returns: image