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 itkRegionOfInterestImageFilter_h
  #define itkRegionOfInterestImageFilter_h
  
  #include "itkImageToImageFilter.h"
  #include "itkSmartPointer.h"
  
  namespace itk
  {
  /** \class RegionOfInterestImageFilter
   * \brief Extract a region of interest from the input image.
   *
   *  This filter produces an output image of the same dimension as the input
   *  image. The user specifies the region of the input image that will be
   *  contained in the output image. The origin coordinates of the output images
   *  will be computed in such a way that if mapped to physical space, the output
   *  image will overlay the input image with perfect registration. In other
   *  words, a registration process between the output image and the input image
   *  will return an identity transform.
   *
   *  If you are interested in changing the dimension of the image, you may want
   *  to consider the ExtractImageFilter. For example for extracting a 2D image
   *  from a slice of a 3D image.
   *
   *  The region to extract is set using the method SetRegionOfInterest.
   *
   * \sa ExtractImageFilter
   *
   * \ingroup GeometricTransform
   * \ingroup ITKImageGrid
   *
   * \wiki
   * \wikiexample{ImageProcessing/RegionOfInterestImageFilter,Extract a portion of an image (region of interest)}
   * \endwiki
   */
  template< typename TInputImage, typename TOutputImage >
  class RegionOfInterestImageFilter:
    public ImageToImageFilter< TInputImage, TOutputImage >
  {
  public:
    /** Standard class typedefs. */
    typedef RegionOfInterestImageFilter                     Self;
    typedef ImageToImageFilter< TInputImage, TOutputImage > Superclass;
    typedef SmartPointer< Self >                            Pointer;
    typedef SmartPointer< const Self >                      ConstPointer;
    typedef typename Superclass::InputImageRegionType       InputImageRegionType;
  
    /** Method for creation through the object factory. */
    itkNewMacro(Self);
  
    /** Run-time type information (and related methods). */
    itkTypeMacro(RegionOfInterestImageFilter, ImageToImageFilter);
  
    /** Typedef to describe the input image region types. */
    typedef typename TInputImage::RegionType RegionType;
    typedef typename TInputImage::IndexType  IndexType;
    typedef typename TInputImage::SizeType   SizeType;
  
    /** Typedef to describe the type of pixel. */
    typedef typename TOutputImage::PixelType OutputImagePixelType;
    typedef typename TInputImage::PixelType  InputImagePixelType;
  
    /** Set/Get the output image region. */
    itkSetMacro(RegionOfInterest, RegionType);
    itkGetConstMacro(RegionOfInterest, RegionType);
  
    /** ImageDimension enumeration */
    itkStaticConstMacro(ImageDimension, unsigned int,
                        TInputImage::ImageDimension);
    itkStaticConstMacro(OutputImageDimension, unsigned int,
                        TOutputImage::ImageDimension);
  
  #ifdef ITK_USE_CONCEPT_CHECKING
    // Begin concept checking
    itkConceptMacro( SameDimensionCheck,
                     ( Concept::SameDimension< ImageDimension, OutputImageDimension > ) );
    itkConceptMacro( InputConvertibleToOutputCheck,
                     ( Concept::Convertible< InputImagePixelType, OutputImagePixelType > ) );
    // End concept checking
  #endif
  
  protected:
    RegionOfInterestImageFilter();
    ~RegionOfInterestImageFilter() {}
    void PrintSelf(std::ostream & os, Indent indent) const ITK_OVERRIDE;
  
    virtual void GenerateInputRequestedRegion() ITK_OVERRIDE;
  
    virtual void EnlargeOutputRequestedRegion(DataObject *output) ITK_OVERRIDE;
  
    /** RegionOfInterestImageFilter can produce an image which is a different
     * size than its input image.  As such, RegionOfInterestImageFilter
     * needs to provide an implementation for
     * GenerateOutputInformation() in order to inform the pipeline
     * execution model.  The original documentation of this method is
     * below.
     *
     * \sa ProcessObject::GenerateOutputInformaton()  */
    virtual void GenerateOutputInformation() ITK_OVERRIDE;
  
    /** RegionOfInterestImageFilter can be implemented as a multithreaded filter.
     * Therefore, this implementation provides a ThreadedGenerateData()
     * routine which is called for each processing thread. The output
     * image data is allocated automatically by the superclass prior to
     * calling ThreadedGenerateData().  ThreadedGenerateData can only
     * write to the portion of the output image specified by the
     * parameter "outputRegionForThread"
     * \sa ImageToImageFilter::ThreadedGenerateData(),
     *     ImageToImageFilter::GenerateData()  */
    void ThreadedGenerateData(const RegionType & outputRegionForThread,
                              ThreadIdType threadId) ITK_OVERRIDE;
  
  private:
    RegionOfInterestImageFilter(const Self &) ITK_DELETE_FUNCTION;
    void operator=(const Self &) ITK_DELETE_FUNCTION;
  
    RegionType m_RegionOfInterest;
  };
  } // end namespace itk
  
  #ifndef ITK_MANUAL_INSTANTIATION
  #include "itkRegionOfInterestImageFilter.hxx"
  #endif
  
  #endif
  