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

  Program:   Insight Segmentation & Registration Toolkit
  Module:    $RCSfile: itkSmoothingRecursiveGaussianImageFilter.txx,v $
  Language:  C++
  Date:      $Date: 2007-09-27 13:55:36 $
  Version:   $Revision: 1.15 $

  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 _itkSmoothingRecursiveGaussianImageFilter_txx
#define _itkSmoothingRecursiveGaussianImageFilter_txx

#include "itkSmoothingRecursiveGaussianImageFilter.h"
#include "itkImageRegionIteratorWithIndex.h"
#include "itkProgressAccumulator.h"

namespace itk
{


/**
 * Constructor
 */
template <typename TInputImage, typename TOutputImage >
SmoothingRecursiveGaussianImageFilter<TInputImage,TOutputImage>
::SmoothingRecursiveGaussianImageFilter()
{

  m_NormalizeAcrossScale = false;

  m_FirstSmoothingFilter = FirstGaussianFilterType::New();
  m_FirstSmoothingFilter->SetOrder( FirstGaussianFilterType::ZeroOrder );
  m_FirstSmoothingFilter->SetDirection( 0 );
  m_FirstSmoothingFilter->SetNormalizeAcrossScale( m_NormalizeAcrossScale );
  m_FirstSmoothingFilter->ReleaseDataFlagOn();

  for( unsigned int i = 0; i<ImageDimension-1; i++ )
    {
    m_SmoothingFilters[ i ] = InternalGaussianFilterType::New();
    m_SmoothingFilters[ i ]->SetOrder( InternalGaussianFilterType::ZeroOrder );
    m_SmoothingFilters[ i ]->SetNormalizeAcrossScale( m_NormalizeAcrossScale );
    m_SmoothingFilters[ i ]->SetDirection( i+1 );
    m_SmoothingFilters[ i ]->ReleaseDataFlagOn();
    }


  m_SmoothingFilters[0]->SetInput( m_FirstSmoothingFilter->GetOutput() );
  for( unsigned int i = 1; i<ImageDimension-1; i++ )
    {
    m_SmoothingFilters[ i ]->SetInput( 
      m_SmoothingFilters[i-1]->GetOutput() );
    }
  
  m_CastingFilter = CastingFilterType::New();
  m_CastingFilter->SetInput(m_SmoothingFilters[ImageDimension-2]->GetOutput());

  //
  // NB: We must call SetSigma in order to initialize the smoothing
  // filters with the default scale.  However, m_Sigma must first be
  // initialized (it is used inside SetSigma) and it must be different
  // from 1.0 or the call will be ignored.
  this->m_Sigma = 0.0;
  this->SetSigma( 1.0 );
}



/**
 * Set value of Sigma
 */
template <typename TInputImage, typename TOutputImage>
void 
SmoothingRecursiveGaussianImageFilter<TInputImage,TOutputImage>
::SetSigma( ScalarRealType sigma )
{
  if (sigma != this->m_Sigma)
    {
    this->m_Sigma = sigma;
    for( unsigned int i = 0; i<ImageDimension-1; i++ )
      {
      m_SmoothingFilters[ i ]->SetSigma( sigma );
      }
    m_FirstSmoothingFilter->SetSigma( sigma );
    
    this->Modified();
    }

}



/**
 * Set Normalize Across Scale Space
 */
template <typename TInputImage, typename TOutputImage>
void 
SmoothingRecursiveGaussianImageFilter<TInputImage,TOutputImage>
::SetNormalizeAcrossScale( bool normalize )
{

  m_NormalizeAcrossScale = normalize;

  for( unsigned int i = 0; i<ImageDimension-1; i++ )
    {
    m_SmoothingFilters[ i ]->SetNormalizeAcrossScale( normalize );
    }
  m_FirstSmoothingFilter->SetNormalizeAcrossScale( normalize );

  this->Modified();

}


//
//
//
template <typename TInputImage, typename TOutputImage>
void
SmoothingRecursiveGaussianImageFilter<TInputImage,TOutputImage>
::GenerateInputRequestedRegion() throw(InvalidRequestedRegionError)
{
  // call the superclass' implementation of this method. this should
  // copy the output requested region to the input requested region
  Superclass::GenerateInputRequestedRegion();

  // This filter needs all of the input
  typename SmoothingRecursiveGaussianImageFilter<TInputImage,TOutputImage>::InputImagePointer image = const_cast<InputImageType *>( this->GetInput() );
  if( image )
    {
    image->SetRequestedRegion( this->GetInput()->GetLargestPossibleRegion() );
    }
}


//
//
//
template <typename TInputImage, typename TOutputImage>
void
SmoothingRecursiveGaussianImageFilter<TInputImage,TOutputImage>
::EnlargeOutputRequestedRegion(DataObject *output)
{
  TOutputImage *out = dynamic_cast<TOutputImage*>(output);

  if (out)
    {
    out->SetRequestedRegion( out->GetLargestPossibleRegion() );
    }
}

/**
 * Compute filter for Gaussian kernel
 */
template <typename TInputImage, typename TOutputImage >
void
SmoothingRecursiveGaussianImageFilter<TInputImage,TOutputImage >
::GenerateData(void)
{

  itkDebugMacro(<< "SmoothingRecursiveGaussianImageFilter generating data ");

  const typename TInputImage::ConstPointer   inputImage( this->GetInput() );

  const typename TInputImage::RegionType region = inputImage->GetRequestedRegion();
  const typename TInputImage::SizeType   size   = region.GetSize();
 
  for( unsigned int d=0; d < ImageDimension; d++)
    {
    if( size[d] < 4 )
      {
      itkExceptionMacro("The number of pixels along dimension " << d << " is less than 4. This filter requires a minimum of four pixels along the dimension to be processed.");
      }
    }


  // Create a process accumulator for tracking the progress of this minipipeline
  ProgressAccumulator::Pointer progress = ProgressAccumulator::New();
  progress->SetMiniPipelineFilter(this);

  // Register the filter with the with progress accumulator using
  // equal weight proportion
  for( unsigned int i = 0; i<ImageDimension-1; i++ )
    {
    progress->RegisterInternalFilter(m_SmoothingFilters[i],1.0 / (ImageDimension));
    }

  progress->RegisterInternalFilter(m_FirstSmoothingFilter,1.0 / (ImageDimension));
  m_FirstSmoothingFilter->SetInput( inputImage );
  // graft our output to the internal filter to force the proper regions
  // to be generated
  m_CastingFilter->GraftOutput( this->GetOutput() );
  m_CastingFilter->Update();
  this->GraftOutput(m_CastingFilter->GetOutput());

}


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

  os << "NormalizeAcrossScale: " << m_NormalizeAcrossScale << std::endl;
  os << "Sigma: " << m_Sigma << std::endl;
}


} // end namespace itk

#endif