class_docstr: This class enables the extraction of image features (Harilick
  features) and basic statistics over a segmentation
class_docstr_tok: ["This","class","enables","the","extraction","of","image","features","(","Harilick","features",")","and","basic","statistics","over","a","segmentation"]
docstr: Calculates the compactness S^1.5/V in terms of probabilistic count,
  binarised count, probabilistic volume, binarised volume
  
  :return:
docstr_tok: ["Calculates","the","compactness","S^1.5\/V","in","terms","of","probabilistic","count",",","binarised","count",",","probabilistic","volume",",","binarised","volume",":","return",":"]
code: def compactness(self):
      """
      Calculates the compactness S^1.5/V in terms of probabilistic count,
      binarised count, probabilistic volume, binarised volume
  
      :return:
      """
      Sn, Snb, Sv, Svb = self.surface()
      Vn, Vnb, Vv, Vvb = self.volume()
      return (
          np.power(Sn, 1.5) / Vn,
          np.power(Snb, 1.5) / Vnb,
          np.power(Sv, 1.5) / Vv,
          np.power(Svb, 1.5) / Vvb,
      )
  
imports: from __future__ import absolute_import, print_function, division
  import numpy
  import numpy.ma
  import math
  import scipy.stats.mstats
  import scipy.ndimage
  from niftynet.utilities.util_common import MorphologyOps, CacheFunctionOutput
label_desc: Use image node_id 36 for calling the RegionProperties obj's underlying member method code with example usage: obj.compactness() and returns: unknown,  unknown,  unknown,  unknown