itkImageClassifierBase.txx

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

  Program:   Insight Segmentation & Registration Toolkit
  Module:    $RCSfile: itkImageClassifierBase.txx,v $
  Language:  C++
  Date:      $Date: 2009-01-24 20:02:54 $
  Version:   $Revision: 1.14 $

  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.

=========================================================================*/
#ifndef __itkImageClassifierBase_txx
#define __itkImageClassifierBase_txx
#include "itkImageClassifierBase.h"

namespace itk
{

template<class TInputImage, 
         class TClassifiedImage>
ImageClassifierBase<TInputImage,TClassifiedImage>
::ImageClassifierBase( void )
{

}

template<class TInputImage, 
         class TClassifiedImage>
ImageClassifierBase<TInputImage, TClassifiedImage>
::~ImageClassifierBase(void)
{

}

template <class TInputImage, 
          class TClassifiedImage>
void
ImageClassifierBase<TInputImage, TClassifiedImage>
::PrintSelf( std::ostream& os, Indent indent ) const
{
  Superclass::PrintSelf(os,indent);

  os << indent << "General Image Classifier / Clusterer" << std::endl;
  os << indent << "ClassifiedImage: ";
  os << m_ClassifiedImage.GetPointer() << std::endl;
  os << indent << "InputImage: ";
  os << m_InputImage.GetPointer() << std::endl;

  signed int i;
  const unsigned int length = static_cast<unsigned int>( m_PixelMembershipValue.size() );
  const signed int last = static_cast<int>( length ) - 1;

  os << indent << "Pixel membership: [";
  for ( i = 0; i < last; i++)
    {
    os << m_PixelMembershipValue[i] << ", ";
    }
  if ( length >= 1 )
    {
    os << m_PixelMembershipValue[last];
    }
  os << "]" << std::endl;

}// end PrintSelf

template <class TInputImage, 
          class TClassifiedImage>
void
ImageClassifierBase<TInputImage, TClassifiedImage>
::GenerateData( )
{
  this->Classify();

}// end Generate data

//------------------------------------------------------------------
// The core function where classification is carried out
//------------------------------------------------------------------
template<class TInputImage, 
         class TClassifiedImage>
void
ImageClassifierBase<TInputImage, TClassifiedImage>
::Classify()
{

  ClassifiedImagePointer  classifiedImage = this->GetClassifiedImage();
  //Check if the an output buffer has been allocated
  if( !classifiedImage )
    {
    this->Allocate();

    //To trigger the pipeline process
    this->Modified();
    }

  //--------------------------------------------------------------------
  // Set the iterators and the pixel type definition for the input image
  //-------------------------------------------------------------------
  InputImageConstPointer  inputImage = this->GetInputImage();
  InputImageConstIterator inIt( inputImage, inputImage->GetBufferedRegion() );

  //--------------------------------------------------------------------
  // Set the iterators and the pixel type definition for the classified image
  //--------------------------------------------------------------------
  classifiedImage = this->GetClassifiedImage();

  ClassifiedImageIterator 
    classifiedIt( classifiedImage, classifiedImage->GetBufferedRegion() );

  //--------------------------------------------------------------------
  //Set up the vector to store the image  data

  InputImagePixelType      inputImagePixel;
  ClassifiedImagePixelType  outputClassifiedLabel;

  //Set up the storage containers to record the probability
  //measures for each class.
  unsigned int numberOfClasses = this->GetNumberOfMembershipFunctions();

  std::vector< double > discriminantScores;
  discriminantScores.resize( numberOfClasses );
  unsigned int classLabel;
  unsigned int classIndex;

  // support progress methods/callbacks
  unsigned long totalPixels = 
    inputImage->GetBufferedRegion().GetNumberOfPixels();
  unsigned long updateVisits = totalPixels / 10;
  if( updateVisits < 1 ) 
    {
    updateVisits = 1;
    }
  int k = 0;

  for ( inIt.GoToBegin(); ! inIt.IsAtEnd(); ++inIt, ++classifiedIt, ++k ) 
    {

    if ( !( k % updateVisits ) )
      {
      this->UpdateProgress((float)k / (float)totalPixels);
      }

    //Read the input vector
    inputImagePixel = inIt.Get();
    for (classIndex = 0; classIndex < numberOfClasses; classIndex++)
      {
      discriminantScores[classIndex] = 
        (this->GetMembershipFunction(classIndex))->Evaluate(inputImagePixel);
      }

    
    classLabel = this->GetDecisionRule()->Evaluate(discriminantScores);
  
    outputClassifiedLabel = ClassifiedImagePixelType ( classLabel );
    classifiedIt.Set( outputClassifiedLabel );
    }// end for (looping throught the dataset)

}// end Classify

template<class TInputImage, 
         class TClassifiedImage>
void
ImageClassifierBase<TInputImage, TClassifiedImage>
::Allocate()
{
  InputImageConstPointer inputImage = this->GetInputImage();
  
  InputImageSizeType inputImageSize = inputImage->GetBufferedRegion().GetSize();
  
  ClassifiedImagePointer classifiedImage =  TClassifiedImage::New();   
  this->SetClassifiedImage(classifiedImage);

  typedef typename TClassifiedImage::IndexType myIndex;
  typename TClassifiedImage::IndexType classifiedImageIndex;
  classifiedImageIndex.Fill(0);

  typename TClassifiedImage::RegionType classifiedImageRegion;

  classifiedImageRegion.SetSize( inputImageSize );
  classifiedImageRegion.SetIndex( classifiedImageIndex );

  classifiedImage->SetLargestPossibleRegion( classifiedImageRegion );
  classifiedImage->SetBufferedRegion( classifiedImageRegion );
  classifiedImage->Allocate();

}

template<class TInputImage, 
         class TClassifiedImage>
const std::vector< double > &
ImageClassifierBase<TInputImage, TClassifiedImage>
::GetPixelMembershipValue(const InputImagePixelType  inputImagePixel)
{
  
  unsigned int numberOfClasses = this->GetNumberOfClasses();
  if( m_PixelMembershipValue.size() != numberOfClasses )
    {
    m_PixelMembershipValue.resize( numberOfClasses );
    }
  
  for (unsigned int classIndex = 0; classIndex < numberOfClasses; classIndex++)
    {
    m_PixelMembershipValue[classIndex] = 
      (this->GetMembershipFunction(classIndex))->Evaluate(inputImagePixel);
    }
 
  //Return the membership value of the 
  return m_PixelMembershipValue;

}


} // namespace itk

#endif