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 __itkMinMaxCurvatureFlowFunction_h
  #define __itkMinMaxCurvatureFlowFunction_h
  
  #include "itkCurvatureFlowFunction.h"
  #include "itkNeighborhoodOperator.h"
  
  namespace itk
  {
  /** \class MinMaxCurvatureFlowFunction
   *
   * This class encapsulate the finite difference equation which drives a
   * min/max curvature flow denoising algorithm.
   *
   * This class uses a zero flux Neumann boundary condition when computing
   * derivatives near the data boundary.
   *
   * This class operates as part of the finite difference solver hierarchy.
   *
   * \sa MinMaxCurvatureFlowImageFilter
   * \sa ZeroFluxNeumannBoundaryCondition
   * \ingroup FiniteDifferenceFunctions
   * \ingroup ITKCurvatureFlow
   */
  template< typename TImage >
  class MinMaxCurvatureFlowFunction:
    public CurvatureFlowFunction< TImage >
  {
  public:
    /**  Standard class typedefs. */
    typedef MinMaxCurvatureFlowFunction     Self;
    typedef CurvatureFlowFunction< TImage > Superclass;
    typedef SmartPointer< Self >            Pointer;
    typedef SmartPointer< const Self >      ConstPointer;
  
    /** Method for creation through the object factory. */
    itkNewMacro(Self);
  
    /** Run-time type information (and related methods) */
    itkTypeMacro(MinMaxCurvatureFlowFunction,
                 CurvatureFlowFunction);
  
    /** Inherit some parameters from the superclass type. */
    typedef typename Superclass::ImageType        ImageType;
    typedef typename Superclass::PixelType        PixelType;
    typedef typename Superclass::RadiusType       RadiusType;
    typedef typename Superclass::NeighborhoodType NeighborhoodType;
    typedef typename Superclass::FloatOffsetType  FloatOffsetType;
  
    /** Extract superclass dimension. */
    itkStaticConstMacro(ImageDimension, unsigned int,
                        Superclass::ImageDimension);
  
    /** Typedef support for the stencil radius. */
    typedef typename RadiusType::SizeValueType RadiusValueType;
  
    /** Set/Get the stencil radius. */
    void SetStencilRadius(const RadiusValueType radius);
  
    const RadiusValueType & GetRadiusValueType() const
    { return m_StencilRadius; }
  
    /** Convenience function for symmetry with SetStencilRadius. */
    const RadiusValueType & GetStencilRadius() const
    { return GetRadiusValueType(); }
  
    /** This method computes the solution update for each pixel that does not
     * lie on a the data set boundary. */
    virtual PixelType ComputeUpdate(const NeighborhoodType & neighborhood,
                                    void *globalData,
                                    const FloatOffsetType & offset = FloatOffsetType(0.0)
                                    );
  
  protected:
    MinMaxCurvatureFlowFunction();
    ~MinMaxCurvatureFlowFunction() {}
  
    typedef Neighborhood< PixelType, itkGetStaticConstMacro(ImageDimension) > StencilOperatorType;
    StencilOperatorType m_StencilOperator;
  
    /** Initialize the stencil opearator to be an N-Dimensional sphere
     * of radius m_StencilRadius. */
    void InitializeStencilOperator();
  
  private:
    MinMaxCurvatureFlowFunction(const Self &); //purposely not implemented
    void operator=(const Self &);              //purposely not implemented
  
    RadiusValueType m_StencilRadius;
  
    // To control overloaded versions of ComputeThreshold
    struct DispatchBase {};
    template< signed int VDimension >
    struct Dispatch: public DispatchBase {};
  
    /** This method computes the threshold by averaging the intensity
     *  in direction perpendicular to the image gradient. */
    virtual PixelType ComputeThreshold(const Dispatch< 2 > &,
                                       const NeighborhoodType & neighborhood) const;
  
    virtual PixelType ComputeThreshold(const Dispatch< 3 > &,
                                       const NeighborhoodType & neighborhood) const;
  
    virtual PixelType ComputeThreshold(const DispatchBase &,
                                       const NeighborhoodType & neighborhood) const;
  };
  } // end namespace itk
  
  #ifndef ITK_MANUAL_INSTANTIATION
  #include "itkMinMaxCurvatureFlowFunction.hxx"
  #endif
  
  #endif
  