code: def total_variation(layer="input"):
      """Total variation of image (or activations at some layer).
  
      This operation is most often used as a penalty to reduce noise.
      See Mahendran, V. 2014. Understanding Deep Image Representations by Inverting Them.
      """
      return lambda T: tf.image.total_variation(T(layer))
  
imports: from __future__ import absolute_import, division, print_function
  from decorator import decorator
  import numpy
  import tensorflow
  from lucid.optvis.objectives_util import _dot, _dot_cossim, _extract_act_pos, _make_arg_str, _T_force_NHWC, _T_handle_batch
label_desc: Use image node_id 9 for calling a global function with example usage: total_variation(layer) and returns: function