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 itkContourMeanDistanceImageFilter_h
  #define itkContourMeanDistanceImageFilter_h
  
  #include "itkImageToImageFilter.h"
  #include "itkNumericTraits.h"
  
  namespace itk
  {
  /** \class ContourMeanDistanceImageFilter
   * \brief Computes the Mean distance between the boundaries of
   * non-zero regions of two images.
   *
   * ContourMeanDistanceImageFilter computes the distance between the
   * set non-zero pixels of two images using the following formula:
   * \f[ H(A,B) = \max(h(A,B),h(B,A)) \f]
   * where
   * \f[ h(A,B) = \mathrm{mean}_{a \in A} \min_{b \in B} \| a - b\| \f] is the dir
  ected
   * Mean distance
   * and \f$A\f$ and \f$B\f$ are respectively the set of non-zero pixels
   * in the first and second input images.
   *
   * In particular, this filter uses the ContourDirectedMeanImageFilter
   * inside to  compute the two directed distances and then select the
   * largest of the two.
   *
   * The Mean distance measures the degree of mismatch between two sets
   * and behaves like a metric over the set of all closed bounded sets -
   * with properties of identity, symmetry and triangle inequality.
   *
   * This filter requires the largest possible region of the first image
   * and the same corresponding region in the second image.
   * It behaves as filter with
   * two input and one output. Thus it can be inserted in a pipeline with
   * other filters. The filter passes the first input through unmodified.
   *
   * This filter is templated over the two input image type. It assume
   * both image have the same number of dimensions.
   *
   * \sa ContourDirectedMeanDistanceImageFilter
   *
   * \author Teo Popa, ISIS Center, Georgetown University
   *
   * \ingroup MultiThreaded
   * \ingroup ITKDistanceMap
   *
   * \wiki
   * \wikiexample{Curves/ContourMeanDistanceImageFilter,Compute the mean distance between all points of two curves}
   * \endwiki
   */
  template< typename TInputImage1, typename TInputImage2 >
  class ContourMeanDistanceImageFilter:
    public ImageToImageFilter< TInputImage1, TInputImage1 >
  {
  public:
    /** Standard Self typedef */
    typedef ContourMeanDistanceImageFilter                   Self;
    typedef ImageToImageFilter< TInputImage1, TInputImage1 > Superclass;
    typedef SmartPointer< Self >                             Pointer;
    typedef SmartPointer< const Self >                       ConstPointer;
  
    /** Method for creation through the object factory. */
    itkNewMacro(Self);
  
    /** Runtime information support. */
    itkTypeMacro(ContourMeanDistanceImageFilter, ImageToImageFilter);
  
    /** Image related typedefs. */
    typedef TInputImage1                        InputImage1Type;
    typedef TInputImage2                        InputImage2Type;
    typedef typename TInputImage1::Pointer      InputImage1Pointer;
    typedef typename TInputImage2::Pointer      InputImage2Pointer;
    typedef typename TInputImage1::ConstPointer InputImage1ConstPointer;
    typedef typename TInputImage2::ConstPointer InputImage2ConstPointer;
  
    typedef typename TInputImage1::RegionType RegionType;
    typedef typename TInputImage1::SizeType   SizeType;
    typedef typename TInputImage1::IndexType  IndexType;
  
    typedef typename TInputImage1::PixelType InputImage1PixelType;
    typedef typename TInputImage2::PixelType InputImage2PixelType;
  
    /** Image related typedefs. */
    itkStaticConstMacro(ImageDimension, unsigned int,
                        TInputImage1::ImageDimension);
  
    /** Type to use form computations. */
    typedef typename NumericTraits< InputImage1PixelType >::RealType RealType;
  
    /** Set the first input. */
    void SetInput1(const InputImage1Type *image);
  
    /** Set the second input. */
    void SetInput2(const InputImage2Type *image);
  
    /** Get the first input. */
    const InputImage1Type * GetInput1();
  
    /** Get the second input. */
    const InputImage2Type * GetInput2();
  
    /** Return the computed Mean distance. */
    itkGetConstMacro(MeanDistance, RealType);
  
    /** Set if image spacing should be used in computing distances. */
    itkSetMacro( UseImageSpacing, bool );
    itkGetConstMacro( UseImageSpacing, bool );
  
  #ifdef ITK_USE_CONCEPT_CHECKING
    // Begin concept checking
    itkConceptMacro( InputHasNumericTraitsCheck,
                     ( Concept::HasNumericTraits< InputImage1PixelType > ) );
    // End concept checking
  #endif
  
  protected:
    ContourMeanDistanceImageFilter();
    ~ContourMeanDistanceImageFilter(){}
    void PrintSelf(std::ostream & os, Indent indent) const ITK_OVERRIDE;
  
    /** GenerateData. */
    void  GenerateData() ITK_OVERRIDE;
  
    // Override since the filter needs all the data for the algorithm
    void GenerateInputRequestedRegion() ITK_OVERRIDE;
  
    // Override since the filter produces all of its output
    void EnlargeOutputRequestedRegion(DataObject *data) ITK_OVERRIDE;
  
  private:
    ContourMeanDistanceImageFilter(const Self &) ITK_DELETE_FUNCTION;
    void operator=(const Self &) ITK_DELETE_FUNCTION;
  
    RealType  m_MeanDistance;
    bool      m_UseImageSpacing;
  }; // end of class
  } // end namespace itk
  
  #ifndef ITK_MANUAL_INSTANTIATION
  #include "itkContourMeanDistanceImageFilter.hxx"
  #endif
  
  #endif
  