// -------------------------------------------------------------------------
// @author Leonardo Florez-Valencia (florez-l@javeriana.edu.co)
// -------------------------------------------------------------------------

#ifndef __CPEXTENSIONS__ALGORITHMS__GAUSSIANDENSITYIMAGEFILTER__H__
#define __CPEXTENSIONS__ALGORITHMS__GAUSSIANDENSITYIMAGEFILTER__H__

#include <itkImageToImageFilter.h>
#include <itkImageScanlineConstIterator.h>
#include <itkImageScanlineIterator.h>
#include <itkProgressReporter.h>

namespace cpExtensions
{
  namespace Algorithms
  {
    /**
     */
    template< class _TInputImage, class _TEstimator >
    class GaussianDensityImageFilter
      : public itk::ImageToImageFilter< _TInputImage, itk::Image< typename _TEstimator::TScalar, _TInputImage::ImageDimension > >
    {
    public:
      typedef typename _TEstimator::TScalar                         TScalar;
      typedef itk::Image< TScalar, _TInputImage::ImageDimension >   TOutputImage;
      typedef GaussianDensityImageFilter                            Self;
      typedef itk::ImageToImageFilter< _TInputImage, TOutputImage > Superclass;
      typedef itk::SmartPointer< Self >                             Pointer;
      typedef itk::SmartPointer< const Self >                       ConstPointer;

      typedef _TInputImage TInputImage;
      typedef _TEstimator  TEstimator;
      typedef typename TOutputImage::RegionType TRegion;

    public:
      itkNewMacro( Self );
      itkTypeMacro( GaussianDensityImageFilter, itkImageToImageFilter );

      itkGetConstObjectMacro( Estimator, TEstimator );
      itkSetConstObjectMacro( Estimator, TEstimator );

    protected:
      GaussianDensityImageFilter( )
        : Superclass( )
        {
        }
      virtual ~GaussianDensityImageFilter( )
        {
        }

      virtual void ThreadedGenerateData(
        const TRegion& region,
        itk::ThreadIdType threadId
        )
        {
          const typename TRegion::SizeType& regionSize = region.GetSize( );
          if( regionSize[ 0 ] == 0 )
            return;
          const TInputImage* in = this->GetInput( );
          TOutputImage* out = this->GetOutput( 0 );

          const size_t nLines = region.GetNumberOfPixels( ) / regionSize[ 0 ];
          itk::ProgressReporter progress( this, threadId, nLines );

          // Define the iterators
          itk::ImageScanlineConstIterator< TInputImage > inIt( in, region );
          itk::ImageScanlineIterator< TOutputImage > outIt( out, region );

          inIt.GoToBegin( );
          outIt.GoToBegin( );
          while( !inIt.IsAtEnd( ) )
          {
            while( !inIt.IsAtEndOfLine( ) )
            {
              if( this->m_Estimator.IsNotNull( ) )
                outIt.Set( this->m_Estimator->Density( inIt.Get( ) ) );
              ++inIt;
              ++outIt;

            } // elihw
            inIt.NextLine( );
            outIt.NextLine( );
            progress.CompletedPixel( );

          } // elihw
        }

    private:
      // Purposely not implemented.
      GaussianDensityImageFilter( const Self& );
      void operator=( const Self& );

    protected:
      typename TEstimator::ConstPointer m_Estimator;
    };

  } // ecapseman

} // ecapseman

#endif // __CPEXTENSIONS__ALGORITHMS__GAUSSIANDENSITYIMAGEFILTER__H__

// eof - $RCSfile$