itkAnchorHistogram.h

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/*=========================================================================

  Program:   Insight Segmentation & Registration Toolkit
  Module:    $RCSfile: itkAnchorHistogram.h,v $
  Language:  C++
  Date:      $Date: 2008-10-20 16:32:08 $
  Version:   $Revision: 1.2 $

  Copyright (c) Insight Software Consortium. All rights reserved.
  See ITKCopyright.txt or http://www.itk.org/HTML/Copyright.htm for details.

     This software is distributed WITHOUT ANY WARRANTY; without even 
     the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR 
     PURPOSE.  See the above copyright notices for more information.

=========================================================================*/

// histogram from the moving histogram operations
#ifndef __itkAnchorHistogram_h
#define __itkAnchorHistogram_h
#include "itkNumericTraits.h"
#include <vector>
#include <map>
#include "itkIndent.h"
namespace itk {

// a simple histogram class hierarchy. One subclass will be maps, the
// other vectors
template <class TInputPixel>
class MorphologyHistogram
{
public:
  MorphologyHistogram() {}
  virtual ~MorphologyHistogram(){}

  virtual void Reset(){}
  
  virtual void AddBoundary(){}

  virtual void RemoveBoundary(){}
  
  virtual void AddPixel(const TInputPixel &){}

  virtual void RemovePixel(const TInputPixel &){}
 
  virtual TInputPixel GetValue()
    {
    return(m_Boundary);  // a dummy return
    }

  void SetBoundary( const TInputPixel & val )
    {
    m_Boundary = val; 
    }
protected:
  TInputPixel  m_Boundary;

};

template <class TInputPixel, class TCompare>
class MorphologyHistogramMap : public MorphologyHistogram<TInputPixel>
{
private:
  typedef typename std::map< TInputPixel, unsigned long, TCompare > MapType;
  
  MapType m_Map;

public:
  MorphologyHistogramMap() 
    {
    }
  ~MorphologyHistogramMap(){}

  void Reset()
    {
    m_Map.clear();
    }
  
  void AddBoundary()
    {
    m_Map[ this->m_Boundary ]++;
    }

  void RemoveBoundary()
    {
    m_Map[ this->m_Boundary ]--; 
    }
  
  void AddPixel(const TInputPixel &p)
    {
    m_Map[ p ]++; 
    }

  void RemovePixel(const TInputPixel &p)
    {
    m_Map[ p ]--; 
    }
 
  TInputPixel GetValue()
    {    // clean the map
    typename MapType::iterator mapIt = m_Map.begin();
    while( mapIt != m_Map.end() )
      {
      if( mapIt->second <= 0 )
        {
        // this value must be removed from the histogram
        // The value must be stored and the iterator updated before removing the value
        // or the iterator is invalidated.
        TInputPixel toErase = mapIt->first;
        mapIt++;
        m_Map.erase( toErase );
        }
      else
        {
        mapIt++;
        // don't remove all the zero value found, just remove the one before the current maximum value
        // the histogram may become quite big on real type image, but it's an important increase of performances
        break;
        }
      }
    
    // and return the value
    return m_Map.begin()->first;
    }

};

template <class TInputPixel, class TCompare>
class MorphologyHistogramVec : public MorphologyHistogram<TInputPixel>
{
public:
  MorphologyHistogramVec() 
    {
    m_Size = static_cast<unsigned int>( NumericTraits< TInputPixel >::max() - 
                                        NumericTraits< TInputPixel >::NonpositiveMin() + 1 );
    m_Vec.resize(m_Size, 0 );
    std::fill(m_Vec.begin(), m_Vec.end(),0);
    if( m_Compare( NumericTraits< TInputPixel >::max(), 
                   NumericTraits< TInputPixel >::NonpositiveMin() ) )
      {
      m_CurrentValue = m_InitVal = NumericTraits< TInputPixel >::NonpositiveMin();
      m_Direction = -1;
      }
    else
      {
      m_CurrentValue = m_InitVal = NumericTraits< TInputPixel >::max();
      m_Direction = 1;
      }
    m_Entries = 0;
    }
  ~MorphologyHistogramVec(){}

  void Reset()
    {
    m_CurrentValue = m_InitVal;
    if (m_Entries != 0)
      {
      std::fill(m_Vec.begin(), m_Vec.end(),0);
      m_Entries = 0;
      }
    }
  
  void AddBoundary()
    {
    AddPixel(this->m_Boundary);
    ++m_Entries;
    }

  void RemoveBoundary()
    {
    RemovePixel(this->m_Boundary);
    --m_Entries;
    }
  
  void AddPixel(const TInputPixel &p)
    {
    
    m_Vec[ (long unsigned int)(p - NumericTraits< TInputPixel >::NonpositiveMin())  ]++;
    if (m_Compare(p, m_CurrentValue))
      {
      m_CurrentValue = p;
      }
    ++m_Entries;
    }

  void RemovePixel(const TInputPixel &p)
    {
    assert((int)p - (int)NumericTraits< TInputPixel >::NonpositiveMin() >= 0);
    assert(((int)p - (int)NumericTraits< TInputPixel >::NonpositiveMin()) < (int)m_Vec.size());
    assert(m_Entries >= 1);
    m_Vec[ (long unsigned int)(p - NumericTraits< TInputPixel >::NonpositiveMin())  ]--; 
    --m_Entries;
    assert(static_cast<int>((int)m_CurrentValue -
                            (int)NumericTraits< TInputPixel >::NonpositiveMin() ) >= 0);
    assert(static_cast<int>((int)m_CurrentValue -
                            (int)NumericTraits< TInputPixel >::NonpositiveMin() ) < (int)m_Vec.size());
    if (m_Entries > 0)
      {
      while( m_Vec[static_cast<int>(m_CurrentValue - 
                                    NumericTraits< TInputPixel >::NonpositiveMin() )] == 0 )
        {
        m_CurrentValue += m_Direction;
        assert(static_cast<int>(m_CurrentValue -
                                NumericTraits< TInputPixel >::NonpositiveMin() ) >= 0);
        assert(static_cast<int>(m_CurrentValue -
                                NumericTraits< TInputPixel >::NonpositiveMin() ) < (int)m_Vec.size());
        }
      }
    }
 
  TInputPixel GetValue()
    { 
    assert(m_Entries > 0);
    return(m_CurrentValue);
    }

private:
  typedef typename std::vector<unsigned long> VecType;
  
  VecType      m_Vec;
  unsigned int m_Size;
  TCompare     m_Compare;
  TInputPixel  m_CurrentValue;
  TInputPixel  m_InitVal;
  int          m_Direction;
  int          m_Entries;

};

} // end namespace itk
#endif