code: def icc_img_to_zscore(icc, center_image=False):
      
      vol = read_img(icc).get_data()
  
      v2 = vol[vol != 0]
      if center_image:
          v2 = detrend(v2, axis=0)
  
      vstd = np.linalg.norm(v2, ord=2) / np.sqrt(np.prod(v2.shape) - 1)
  
      eps = np.finfo(vstd.dtype).eps
      vol /= (eps + vstd)
  
      return vol
docs: Return a z-scored version of `icc`.
      This function is based on GIFT `icatb_convertImageToZScores` function.