itkWindowedSincInterpolateImageFunction.h

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 *
 *  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.
 *
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#ifndef itkWindowedSincInterpolateImageFunction_h
#define itkWindowedSincInterpolateImageFunction_h

#include "itkConstNeighborhoodIterator.h"
#include "itkZeroFluxNeumannBoundaryCondition.h"
#include "itkInterpolateImageFunction.h"

namespace itk
{
namespace Function
{
template< unsigned int VRadius,
          typename TInput = double, typename TOutput = double >
class ITK_TEMPLATE_EXPORT CosineWindowFunction
{
public:
  inline TOutput operator()(const TInput & A) const
  { return static_cast<TOutput>(std::cos(A * m_Factor)); }

private:
  static const double m_Factor;
};

template< unsigned int VRadius,
          typename TInput = double, typename TOutput = double >
class ITK_TEMPLATE_EXPORT HammingWindowFunction
{
public:
  inline TOutput operator()(const TInput & A) const
  { return static_cast<TOutput>(0.54 + 0.46 * std::cos(A * m_Factor) ); }

private:
  static const double m_Factor;
};

template< unsigned int VRadius,
          typename TInput = double, typename TOutput = double >
class ITK_TEMPLATE_EXPORT WelchWindowFunction
{
public:
  inline TOutput operator()(const TInput & A) const
  { return static_cast<TOutput>( 1.0 - A * m_Factor * A ); }

private:
  static const double m_Factor;
};

template< unsigned int VRadius,
          typename TInput = double, typename TOutput = double >
class ITK_TEMPLATE_EXPORT LanczosWindowFunction
{
public:
  inline TOutput operator()(const TInput & A) const
  {
    if ( A == 0.0 ) { return static_cast<TOutput>(1.0); }
    double z = m_Factor * A;
    return static_cast<TOutput>( std::sin(z) / z );
  }

private:
  static const double m_Factor;
};

template< unsigned int VRadius,
          typename TInput = double, typename TOutput = double >
class ITK_TEMPLATE_EXPORT BlackmanWindowFunction
{
public:
  inline TOutput operator()(const TInput & A) const
  {
    return static_cast<TOutput>
           ( 0.42 + 0.5 * std::cos(A * m_Factor1) + 0.08 * std::cos(A * m_Factor2) );
  }

private:
  static const double m_Factor1;

  static const double m_Factor2;
};
} // namespace Function

template<
  typename TInputImage,
  unsigned int VRadius,
  typename TWindowFunction = Function::HammingWindowFunction< VRadius >,
  class TBoundaryCondition = ZeroFluxNeumannBoundaryCondition< TInputImage, TInputImage >,
  class TCoordRep = double >
class WindowedSincInterpolateImageFunction:
  public InterpolateImageFunction< TInputImage, TCoordRep >
{
public:
  ITK_DISALLOW_COPY_AND_ASSIGN(WindowedSincInterpolateImageFunction);

  using Self = WindowedSincInterpolateImageFunction;
  using Superclass = InterpolateImageFunction< TInputImage, TCoordRep >;

  using Pointer = SmartPointer< Self >;
  using ConstPointer = SmartPointer< const Self >;

  itkTypeMacro(WindowedSincInterpolateImageFunction,
               InterpolateImageFunction);

  itkNewMacro(Self);

  using OutputType = typename Superclass::OutputType;

  using InputImageType = typename Superclass::InputImageType;

  using RealType = typename Superclass::RealType;

  static constexpr unsigned int ImageDimension = Superclass::ImageDimension;

  using IndexType = typename Superclass::IndexType;
  using IndexValueType = typename Superclass::IndexValueType;

  using ImageType = TInputImage;

  using ContinuousIndexType = typename Superclass::ContinuousIndexType;

  void SetInputImage(const ImageType *image) override;

  OutputType EvaluateAtContinuousIndex(
    const ContinuousIndexType & index) const override;

protected:
  WindowedSincInterpolateImageFunction();
  ~WindowedSincInterpolateImageFunction() override;
  void PrintSelf(std::ostream & os, Indent indent) const override;

private:
  // Internal type alias
  using IteratorType = ConstNeighborhoodIterator<
    ImageType, TBoundaryCondition >;

  // Constant to store twice the radius
  static const unsigned int m_WindowSize;

  TWindowFunction m_WindowFunction;

  unsigned int *m_OffsetTable;

  unsigned int m_OffsetTableSize;

  unsigned int **m_WeightOffsetTable;

  inline double Sinc(double x) const
  {
    double px = itk::Math::pi * x;

    return ( x == 0.0 ) ? 1.0 : std::sin(px) / px;
  }
};
} // namespace itk

#ifndef ITK_MANUAL_INSTANTIATION
#include "itkWindowedSincInterpolateImageFunction.hxx"
#endif

#endif // _itkWindowedSincInterpolateImageFunction_h