ITK  5.0.0
Insight Segmentation and Registration Toolkit
itkHistogramToEntropyImageFilter.h
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18 #ifndef itkHistogramToEntropyImageFilter_h
19 #define itkHistogramToEntropyImageFilter_h
20 
22 
23 namespace itk
24 {
52 namespace Function
53 {
54 template< typename TInput, typename TOutput = double >
56 {
57 public:
58 
59  //Probability function = Number of occurrences in each bin /
60  // Total Number of occurrences.
61  //
62  // Returns pixels of float..
63  using OutputPixelType = TOutput;
64 
66  {}
67 
68  ~HistogramEntropyFunction() = default;
69 
70  inline OutputPixelType operator()(const TInput & A) const
71  {
72  if ( A )
73  {
74  const double p = static_cast< OutputPixelType >( A )
75  / static_cast< OutputPixelType >( m_TotalFrequency );
76  return static_cast< OutputPixelType >( ( -1 ) * p * std::log(p) / std::log(2.0) );
77  }
78  else
79  {
80  const double p = static_cast< OutputPixelType >( A + 1 )
81  / static_cast< OutputPixelType >( m_TotalFrequency );
82  return static_cast< OutputPixelType >( ( -1 ) * p * std::log(p) / std::log(2.0) );
83  }
84  }
85 
87  {
88  m_TotalFrequency = n;
89  }
90 
92  {
93  return m_TotalFrequency;
94  }
95 
96 private:
98 };
99 }
100 
101 template< typename THistogram, typename TImage=Image< double, 3> >
103  public HistogramToImageFilter< THistogram, TImage,
104  Function::HistogramEntropyFunction< SizeValueType, typename TImage::PixelType > >
105 {
106 public:
107  ITK_DISALLOW_COPY_AND_ASSIGN(HistogramToEntropyImageFilter);
108 
111 
113  using Superclass = HistogramToImageFilter< THistogram, TImage,
115 
118 
121 
123  itkNewMacro(Self);
124 
125 protected:
126  HistogramToEntropyImageFilter() = default;
127  ~HistogramToEntropyImageFilter() override = default;
128 };
129 } // end namespace itk
130 
131 #endif
Light weight base class for most itk classes.
unsigned long SizeValueType
Definition: itkIntTypes.h:83
~HistogramToEntropyImageFilter() override=default
This class takes a histogram as an input and returns an image of type specified by the functor...
The class takes a histogram as an input and gives the entropy image as the output. A pixel, at position I, in the output image is given by.
OutputPixelType operator()(const TInput &A) const