itkRegionOfInterestImageFilter.txx

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

  Program:   Insight Segmentation & Registration Toolkit
  Module:    $RCSfile: itkRegionOfInterestImageFilter.txx,v $
  Language:  C++
  Date:      $Date: 2008-12-18 17:49:58 $
  Version:   $Revision: 1.17 $

  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 __itkRegionOfInterestImageFilter_txx
#define __itkRegionOfInterestImageFilter_txx

#include "itkRegionOfInterestImageFilter.h"
#include "itkImageRegionIterator.h"
#include "itkImageRegionConstIterator.h"
#include "itkObjectFactory.h"
#include "itkProgressReporter.h"
#include "itkImage.h"

namespace itk
{

template <class TInputImage, class TOutputImage>
RegionOfInterestImageFilter<TInputImage,TOutputImage>
::RegionOfInterestImageFilter() 
{
}


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

  os << indent << "RegionOfInterest: " << m_RegionOfInterest << std::endl;
}

template <class TInputImage, class TOutputImage>
void 
RegionOfInterestImageFilter<TInputImage,TOutputImage>
::GenerateInputRequestedRegion()
{
  // call the superclass' implementation of this method
  Superclass::GenerateInputRequestedRegion();
  
  // get pointer to the input 
  typename Superclass::InputImagePointer  inputPtr = 
    const_cast< TInputImage * >( this->GetInput() );

  if( inputPtr )
    {
    // request the region of interest
    inputPtr->SetRequestedRegion( m_RegionOfInterest );
    }
}

template <class TInputImage, class TOutputImage>
void 
RegionOfInterestImageFilter<TInputImage,TOutputImage>
::EnlargeOutputRequestedRegion(DataObject *output)
{
  // call the superclass' implementation of this method
  Superclass::EnlargeOutputRequestedRegion(output);
  
  // generate everything in the region of interest
  output->SetRequestedRegionToLargestPossibleRegion();
}

template <class TInputImage, class TOutputImage>
void 
RegionOfInterestImageFilter<TInputImage,TOutputImage>
::GenerateOutputInformation()
{
  // do not call the superclass' implementation of this method since
  // this filter allows the input the output to be of different dimensions
 
  // get pointers to the input and output
  typename Superclass::OutputImagePointer      outputPtr = this->GetOutput();
  typename Superclass::InputImageConstPointer  inputPtr  = this->GetInput();

  if ( !outputPtr || !inputPtr)
    {
    return;
    }

  // Set the output image size to the same value as the region of interest.
  RegionType region;
  IndexType  start;
  start.Fill(0);

  region.SetSize( m_RegionOfInterest.GetSize() );
  region.SetIndex( start );
 
  // Copy Information without modification.
  outputPtr->CopyInformation( inputPtr );

  // Adjust output region
  outputPtr->SetLargestPossibleRegion(region);

  // Correct origin of the extracted region.
  IndexType roiStart( m_RegionOfInterest.GetIndex() );
  typename Superclass::OutputImageType::PointType  outputOrigin;
  inputPtr->TransformIndexToPhysicalPoint( roiStart, outputOrigin);
  outputPtr->SetOrigin( outputOrigin );

}

template <class TInputImage, class TOutputImage>
void 
RegionOfInterestImageFilter<TInputImage,TOutputImage>
::ThreadedGenerateData(const RegionType& outputRegionForThread,
                       int threadId)
{
  itkDebugMacro(<<"Actually executing");

  // Get the input and output pointers
  typename Superclass::InputImageConstPointer  inputPtr  = this->GetInput();
  typename Superclass::OutputImagePointer      outputPtr = this->GetOutput();

  // support progress methods/callbacks
  ProgressReporter progress(this, threadId, outputRegionForThread.GetNumberOfPixels());
  
  // Define the portion of the input to walk for this thread
  InputImageRegionType inputRegionForThread;
  inputRegionForThread.SetSize( outputRegionForThread.GetSize() );

  IndexType start;
  IndexType roiStart(    m_RegionOfInterest.GetIndex()    );
  IndexType threadStart( outputRegionForThread.GetIndex() );
  for(unsigned int i=0; i<ImageDimension; i++)
    {
    start[i] = roiStart[i] + threadStart[i];
    }

  inputRegionForThread.SetIndex( start );
  
  // Define the iterators.
  typedef ImageRegionIterator<TOutputImage>     OutputIterator;
  typedef ImageRegionConstIterator<TInputImage> InputIterator;

  OutputIterator outIt(outputPtr, outputRegionForThread);
  InputIterator inIt(inputPtr, inputRegionForThread);

  // walk the output region, and sample the input image
  while( !outIt.IsAtEnd() )
    {
    // copy the input pixel to the output
    outIt.Set( inIt.Get());
    ++outIt; 
    ++inIt; 
    progress.CompletedPixel();
    }
}

} // end namespace itk

#endif