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.
 *
 *=========================================================================*/
#ifndef __itkWindowedSincInterpolateImageFunction_h
#define __itkWindowedSincInterpolateImageFunction_h

#include "itkConstNeighborhoodIterator.h"
#include "itkConstantBoundaryCondition.h"
#include "itkInterpolateImageFunction.h"

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

private:
  static const double m_Factor;
};

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

private:
  static const double m_Factor;
};

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

private:
  static const double m_Factor;
};

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

private:
  static const double m_Factor;
};

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

private:
  static const double m_Factor1;

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

template<
  class TInputImage,
  unsigned int VRadius,
  class TWindowFunction = Function::HammingWindowFunction< VRadius >,
  class TBoundaryCondition = ConstantBoundaryCondition< TInputImage >,
  class TCoordRep = double >
class ITK_EXPORT WindowedSincInterpolateImageFunction:
  public InterpolateImageFunction< TInputImage, TCoordRep >
{
public:

  typedef WindowedSincInterpolateImageFunction               Self;
  typedef InterpolateImageFunction< TInputImage, TCoordRep > Superclass;

  typedef SmartPointer< Self >       Pointer;
  typedef SmartPointer< const Self > ConstPointer;

  itkTypeMacro(WindowedSincInterpolateImageFunction,
               InterpolateImageFunction);

  itkNewMacro(Self);

  typedef typename Superclass::OutputType OutputType;

  typedef typename Superclass::InputImageType InputImageType;

  typedef typename Superclass::RealType RealType;

  itkStaticConstMacro(ImageDimension, unsigned int, Superclass::ImageDimension);

  typedef typename Superclass::IndexType      IndexType;
  typedef typename Superclass::IndexValueType IndexValueType;

  typedef TInputImage ImageType;

  typedef typename Superclass::ContinuousIndexType ContinuousIndexType;

  virtual void SetInputImage(const ImageType *image);

  virtual OutputType EvaluateAtContinuousIndex(
    const ContinuousIndexType & index) const;

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

private:
  WindowedSincInterpolateImageFunction(const Self &); //not implemented
  void operator=(const Self &);                       //purposely not
                                                      // implemented

  // Internal typedefs
  typedef ConstNeighborhoodIterator<
    ImageType, TBoundaryCondition > IteratorType;

  // 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 = vnl_math::pi * x;

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

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

#endif // _itkWindowedSincInterpolateImageFunction_h