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 itkBinaryMagnitudeImageFilter_h
  #define itkBinaryMagnitudeImageFilter_h
  
  #include "itkBinaryFunctorImageFilter.h"
  
  namespace itk
  {
  namespace Functor
  {
  /**
   * \class Modulus2
   * \brief
   * \ingroup ITKImageIntensity
   */
  template< typename TInput1, typename TInput2, typename TOutput >
  class Modulus2
  {
  public:
    Modulus2() {}
    ~Modulus2() {}
    bool operator!=(const Modulus2 &) const
    {
      return false;
    }
  
    bool operator==(const Modulus2 & other) const
    {
      return !( *this != other );
    }
  
    inline TOutput operator()(const TInput1 & A,
                              const TInput2 & B) const
    {
      const double dA = static_cast< double >( A );
      const double dB = static_cast< double >( B );
  
      return static_cast< TOutput >( std::sqrt(dA * dA + dB * dB) );
    }
  };
  }
  /** \class BinaryMagnitudeImageFilter
   * \brief Computes the square root of the sum of squares of corresponding input pixels.
   *
   * This filter is templated over the types of the two
   * input images and the type of the output image.
   *
   * Numeric conversions (castings) are done by the C++ defaults.
   *
   * The filter walks over all of the pixels in the two input images, and for
   * each pixel does the following:
   *
   * \li cast the input 1 pixel value to \c double
   * \li cast the input 2 pixel value to \c double
   * \li compute the sum of squares of the two pixel values
   * \li compute the square root of the sum
   * \li cast the \c double value resulting from \c std::sqrt() to the pixel type of the output image
   * \li store the cast value into the output image.
   *
   * The filter expects all images to have the same dimension
   * (e.g. all 2D, or all 3D, or all ND)
   *
   * \ingroup IntensityImageFilters
   * \ingroup MultiThreaded
   * \ingroup ITKImageIntensity
   */
  template< typename TInputImage1, typename TInputImage2, typename TOutputImage >
  class BinaryMagnitudeImageFilter:
    public
    BinaryFunctorImageFilter< TInputImage1, TInputImage2, TOutputImage,
                              Functor::Modulus2<
                                typename TInputImage1::PixelType,
                                typename TInputImage2::PixelType,
                                typename TOutputImage::PixelType >   >
  {
  public:
    /** Standard class typedefs. */
    typedef BinaryMagnitudeImageFilter Self;
    typedef BinaryFunctorImageFilter< TInputImage1, TInputImage2, TOutputImage,
                                      Functor::Modulus2<
                                        typename TInputImage1::PixelType,
                                        typename TInputImage2::PixelType,
                                        typename TOutputImage::PixelType >
                                      >                                   Superclass;
    typedef SmartPointer< Self >       Pointer;
    typedef SmartPointer< const Self > ConstPointer;
  
    /** Method for creation through the object factory. */
    itkNewMacro(Self);
  
    /** Runtime information support. */
    itkTypeMacro(BinaryMagnitudeImageFilter,
                 BinaryFunctorImageFilter);
  
  #ifdef ITK_USE_CONCEPT_CHECKING
    // Begin concept checking
    itkConceptMacro( Input1ConvertibleToDoubleCheck,
                     ( Concept::Convertible< typename TInputImage1::PixelType, double > ) );
    itkConceptMacro( Input2ConvertibleToDoubleCheck,
                     ( Concept::Convertible< typename TInputImage2::PixelType, double > ) );
    itkConceptMacro( DoubleConvertibleToOutputCheck,
                     ( Concept::Convertible< double, typename TOutputImage::PixelType > ) );
    // End concept checking
  #endif
  
  protected:
    BinaryMagnitudeImageFilter() {}
    virtual ~BinaryMagnitudeImageFilter() ITK_OVERRIDE {}
  
  private:
    ITK_DISALLOW_COPY_AND_ASSIGN(BinaryMagnitudeImageFilter);
  };
  } // end namespace itk
  
  #endif
  