class_docstr: RGB histogram equilisation. Unlike the multi-modality general
  histogram normalisation this is done conventionally, on a
  per-image basis. This layer requires OpenCV.
code: def __init__(self, image_name, name="rgb_normaliser"):
      super(RGBHistogramEquilisationLayer, self).__init__(name=name)
  
      self.image_name = image_name
  
file_path: NiftyNet/niftynet/layer/rgb_histogram_equilisation.py
imports: from __future__ import absolute_import, print_function
  import numpy
  from niftynet.layer.base_layer import Layer
  from niftynet.utilities.util_import import require_module
label_desc: Use image node_id 1 to create a new RGBHistogramEquilisationLayer object from inherited base classes: Layer with example: obj = RGBHistogramEquilisationLayer(image_name, name)