code: def _add_third_dim(image_arr_2dim: np.ndarray) -> np.ndarray:
      """
      Converts a 2-d image array to 3-d by repeating the array thrice along the 3rd dimension.
  
      Args:
          image_arr_2dim: 2-dimensional image array.
  
      Returns:
          An expanded 3-dimensional numpy image array with input 2-dimensional array repeated along the 3rd dimension.
      """
      image_arr_3dim = np.tile(
          image_arr_2dim[..., np.newaxis], (1, 1, 3)
      )  # convert (x, y) to (x, y, 3) (grayscale to rgb)
      return image_arr_3dim
  
file_path: imagededup/imagededup/utils/image_utils.py
imports: from pathlib import PurePath
  from typing import List, Union, Tuple
  import numpy
  from PIL import Image
  from imagededup.utils.logger import return_logger
label_desc: Use image node_id 2 for calling a global function with example usage: _add_third_dim(image_arr_2dim) and returns: image_arr_3dim