docs: def suppxl_ints2im(suppxls, suppxl_ints=None, im=None):
      """Replaces superpixel labels with their mean value.
      inputs:
          suppxls ... image with suppxls labels, ndarray
          suppxl_intens ... vector with suppxls mean intensities
          im ... input image
      outputs:
          suppxl_ints_im ... image with suppxls mean intensities, ndarray same shape as suppxls
      """
  
      suppxl_ints_im = np.zeros(suppxls.shape)
  
      if suppxl_ints is None and im is not None:
          suppxl_ints = get_superpxl_intensities(im, suppxls)
  
      for i in np.unique(suppxls):
          sup = suppxls == i
          val = suppxl_ints[i]
          suppxl_ints_im[np.nonzero(sup)] = val
  
      return suppxl_ints_im