text: /*=========================================================================
   *
   *  Copyright Insight Software Consortium
   *
   *  Licensed under the Apache License, Version 2.0 (the "License");
   *  you may not use this file except in compliance with the License.
   *  You may obtain a copy of the License at
   *
   *         http://www.apache.org/licenses/LICENSE-2.0.txt
   *
   *  Unless required by applicable law or agreed to in writing, software
   *  distributed under the License is distributed on an "AS IS" BASIS,
   *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   *  See the License for the specific language governing permissions and
   *  limitations under the License.
   *
   *=========================================================================*/
  
  #ifndef itkFFTPadImageFilter_hxx
  #define itkFFTPadImageFilter_hxx
  
  #include "itkFFTPadImageFilter.h"
  #include "itkProgressAccumulator.h"
  #include "itkNumericTraits.h"
  #include "itkPadImageFilter.h"
  #include "itkChangeInformationImageFilter.h"
  #include "itkForwardFFTImageFilter.h"
  #include "itkMath.h"
  
  namespace itk
  {
  
  template <class TInputImage, class TOutputImage>
  FFTPadImageFilter<TInputImage, TOutputImage>
  ::FFTPadImageFilter()
  {
    typedef Image< float, TInputImage::ImageDimension > RealImageType;
    typedef ForwardFFTImageFilter< RealImageType >      FFTFilterType;
    m_SizeGreatestPrimeFactor = FFTFilterType::New()->GetSizeGreatestPrimeFactor();
    Self::InternalSetBoundaryCondition( &m_DefaultBoundaryCondition );
  }
  
  
  template <class TInputImage, class TOutputImage>
  void
  FFTPadImageFilter<TInputImage, TOutputImage>
  ::GenerateOutputInformation()
  {
    // call the superclass' implementation of this method
    Superclass::GenerateOutputInformation();
  
    const InputImageType * input0 = this->GetInput();
    OutputImageType * output0 = this->GetOutput();
  
    RegionType region0 = input0->GetLargestPossibleRegion();
    SizeType size;
    IndexType index;
    for( unsigned int i=0; i<ImageDimension; ++i )
      {
      SizeValueType padSize = 0;
      if( m_SizeGreatestPrimeFactor > 1 )
        {
        while( Math::GreatestPrimeFactor( region0.GetSize()[i] + padSize ) > m_SizeGreatestPrimeFactor )
          {
          ++padSize;
          }
        }
      else if( m_SizeGreatestPrimeFactor == 1 )
        {
        // make sure the total size is even
        padSize += ( region0.GetSize()[i] + padSize ) % 2;
        }
      index[i] = region0.GetIndex()[i] - padSize/2;
      size[i] = region0.GetSize()[i] + padSize;
      }
    RegionType region( index, size );
    output0->SetLargestPossibleRegion( region );
  }
  
  
  template<class TInputImage, class TOutputImage>
  void
  FFTPadImageFilter<TInputImage, TOutputImage>
  ::PrintSelf(std::ostream &os, Indent indent) const
  {
    Superclass::PrintSelf(os, indent);
  
    os << indent << "SizeGreatestPrimeFactor: "  << m_SizeGreatestPrimeFactor << std::endl;
  }
  
  }// end namespace itk
  #endif
  