code: def _sim_colour(r1, r2):
      """
      calculate the sum of histogram intersection of colour
      """
      return sum(
          [min(a, b) for a, b in zip(r1["hist_c"], r2["hist_c"])]
      )
  
imports: import sys
  from past.builtins import cmp
  import skimage.io
  import skimage.feature
  import skimage.color
  import skimage.transform
  import skimage.util
  import skimage.segmentation
  import numpy
label_desc: Use image node_id 2 for calling a global function with example usage: _sim_colour(r1, r2) and returns: sum