00001 /*========================================================================= 00002 00003 Program: Insight Segmentation & Registration Toolkit 00004 Module: $RCSfile: itkHistogramToEntropyImageFilter.h,v $ 00005 Language: C++ 00006 Date: $Date: 2009-04-01 14:36:37 $ 00007 Version: $Revision: 1.10 $ 00008 00009 Copyright (c) Insight Software Consortium. All rights reserved. 00010 See ITKCopyright.txt or http://www.itk.org/HTML/Copyright.htm for details. 00011 00012 This software is distributed WITHOUT ANY WARRANTY; without even 00013 the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR 00014 PURPOSE. See the above copyright notices for more information. 00015 00016 =========================================================================*/ 00017 #ifndef __itkHistogramToEntropyImageFilter_h 00018 #define __itkHistogramToEntropyImageFilter_h 00019 00020 #include "itkHistogramToImageFilter.h" 00021 00022 namespace itk 00023 { 00024 00051 namespace Function { 00052 template< class TInput, class TOutput=double > 00053 class HistogramEntropyFunction 00054 { 00055 public: 00056 00057 //Probability function = Number of occurances in each bin / 00058 // Total Number of occurances. 00059 // 00060 // Returns pixels of float.. 00061 typedef TOutput OutputPixelType; 00062 00063 00064 HistogramEntropyFunction(): 00065 m_TotalFrequency(1) {} 00066 00067 ~HistogramEntropyFunction() {}; 00068 00069 inline OutputPixelType operator()( const TInput & A ) const 00070 { 00071 if( A ) 00072 { 00073 const double p = static_cast<OutputPixelType>(A) / 00074 static_cast<OutputPixelType>(m_TotalFrequency); 00075 return static_cast<OutputPixelType>( (-1) * p * vcl_log(p) / vcl_log(2.0)); 00076 } 00077 else 00078 { 00079 const double p = static_cast<OutputPixelType>(A+1) / 00080 static_cast<OutputPixelType>(m_TotalFrequency); 00081 return static_cast<OutputPixelType>( (-1) * p * vcl_log(p) / vcl_log(2.0)); 00082 } 00083 } 00084 00085 void SetTotalFrequency( const unsigned long n ) 00086 { 00087 m_TotalFrequency = n; 00088 } 00089 00090 unsigned long GetTotalFrequency() const 00091 { 00092 return m_TotalFrequency; 00093 } 00094 00095 private: 00096 unsigned long m_TotalFrequency; 00097 }; 00098 } 00099 00100 template <class THistogram, class TOutputPixel=double > 00101 class ITK_EXPORT HistogramToEntropyImageFilter : 00102 public HistogramToImageFilter< THistogram, 00103 Function::HistogramEntropyFunction< unsigned long, TOutputPixel > > 00104 { 00105 public: 00106 00108 typedef HistogramToEntropyImageFilter Self; 00109 00111 typedef HistogramToImageFilter< THistogram, 00112 Function::HistogramEntropyFunction< unsigned long, TOutputPixel > > 00113 Superclass; 00114 00115 typedef SmartPointer<Self> Pointer; 00116 typedef SmartPointer<const Self> ConstPointer; 00117 00119 itkTypeMacro( HistogramToEntropyImageFilter, HistogramToImageFilter ); 00120 00122 itkNewMacro(Self); 00123 00124 protected: 00125 HistogramToEntropyImageFilter() {} 00126 virtual ~HistogramToEntropyImageFilter() {} 00127 00128 private: 00129 HistogramToEntropyImageFilter(const Self&); //purposely not implemented 00130 void operator=(const Self&); //purposely not implemented 00131 00132 }; 00133 00134 } // end namespace itk 00135 00136 #endif 00137