text: import numpy as np
  
  
  def split_images_by_depth(concatenated_images, image_depth=3):
      assert concatenated_images.shape[2] % image_depth == 0
      split_images = tuple(np.split(concatenated_images, concatenated_images.shape[2] / image_depth, axis=-1))
      return split_images
  
  
  def stack_images_by_depth(list_of_images):
      return np.concatenate(list_of_images, axis=-1)
  
  
  def concatenate_images_by_width(list_of_images):
      return np.concatenate(list_of_images, axis=1)
  
  
  def concatenate_images_by_height(list_of_images):
      return np.concatenate(list_of_images, axis=0)
  
  