code: def get_light_map_single(img):
      gray = img
      gray = gray[None]
      gray = gray.transpose((1, 2, 0))
      blur = cv2.GaussianBlur(gray, (0, 0), 3)
      gray = gray.reshape((gray.shape[0], gray.shape[1]))
      highPass = gray.astype(int) - blur.astype(int)
      highPass = highPass.astype(np.float32)
      highPass = highPass / 128.0
      return highPass
  
imports: import numpy
  import cv2
  from scipy import ndimage
label_desc: Use image node_id 4 for calling a global function with example usage: get_light_map_single(img) and returns: highPass