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 itkFrameDifferenceVideoFilter_h
  #define itkFrameDifferenceVideoFilter_h
  
  #include "itkVideoToVideoFilter.h"
  
  namespace itk
  {
  
  /** \class FrameDifferenceVideoFilter
   * \brief Compute the squared intensity difference between frame x and frame
   * x+n
   *
   * This filter computes the squared intensity difference between a frame and
   * the nth previous frame.
   *
   * \ingroup ITKVideoFiltering
   */
  template<typename TInputVideoStream, typename TOutputVideoStream>
  class ITK_TEMPLATE_EXPORT FrameDifferenceVideoFilter :
    public VideoToVideoFilter<TInputVideoStream, TOutputVideoStream>
  {
  public:
    ITK_DISALLOW_COPY_AND_ASSIGN(FrameDifferenceVideoFilter);
  
    /** Standard class type aliases */
    using InputVideoStreamType = TInputVideoStream;
    using OutputVideoStreamType = TOutputVideoStream;
    using Self = FrameDifferenceVideoFilter< InputVideoStreamType,
                                     OutputVideoStreamType >;
    using Superclass = VideoToVideoFilter< InputVideoStreamType,
                                OutputVideoStreamType >;
    using Pointer = SmartPointer< Self >;
    using ConstPointer = SmartPointer< const Self >;
    using ConstWeakPointer = WeakPointer< const Self >;
  
    using InputFrameType = typename TInputVideoStream::FrameType;
    using InputPixelType = typename InputFrameType::PixelType;
    using InputFrameSpatialRegionType = typename InputFrameType::RegionType;
    using OutputFrameType = typename TOutputVideoStream::FrameType;
    using OutputPixelType = typename OutputFrameType::PixelType;
    using OutputFrameSpatialRegionType = typename OutputFrameType::RegionType;
  
    itkNewMacro(Self);
  
    itkTypeMacro(FrameDifferenceVideoFilter, VideoToVideoFilter);
  
    /** Get/Set the offset for computing frame differences. Defaults to 1. */
    void SetFrameOffset(SizeValueType numFrames);
    SizeValueType GetFrameOffset();
  
  protected:
  
    /** Constructor and Destructor */
    FrameDifferenceVideoFilter();
    ~FrameDifferenceVideoFilter() override {}
  
    /** PrintSelf */
    void PrintSelf(std::ostream & os, Indent indent) const override;
  
    /** FrameDifferenceVideoFilter is implemented as a temporal streaming and
     * spatially multithreaded filter, so we override ThreadedGenerateData */
    void ThreadedGenerateData(
                  const OutputFrameSpatialRegionType& outputRegionForThread,
                  int threadId) override;
  
  private:
  
  };  // end class FrameDifferenceVideoFilter
  
  } // end namespace itk
  
  #ifndef ITK_MANUAL_INSTANTIATION
  #include "itkFrameDifferenceVideoFilter.hxx"
  #endif
  
  #endif
  