code: def get_hist(image):
      hist = cv2.calcHist(
          [cv2.cvtColor(image, cv2.COLOR_BGR2Lab)],
          [0, 1],
          None,
          [128, 128],
          [0, 256, 0, 256],
      )
      return cv2.normalize(hist, hist).flatten()
  
imports: import cv2
  from norfair import Detection
label_desc: Use image node_id 2 for calling a global function with example usage: get_hist(image) and returns: cv2