/*=========================================================================

  Program:   Insight Segmentation & Registration Toolkit
  Module:    $RCSfile: itkBinaryMedianImageFilter.h,v $
  Language:  C++
  Date:      $Date: 2008-10-09 15:31:36 $
  Version:   $Revision: 1.6 $

  Copyright (c) Insight Software Consortium. All rights reserved.
  See ITKCopyright.txt or http://www.itk.org/HTML/Copyright.htm for details.

     This software is distributed WITHOUT ANY WARRANTY; without even 
     the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR 
     PURPOSE.  See the above copyright notices for more information.

=========================================================================*/
#ifndef __itkBinaryMedianImageFilter_h
#define __itkBinaryMedianImageFilter_h

#include "itkImageToImageFilter.h"
#include "itkImage.h"

namespace itk
{
/** \class BinaryMedianImageFilter
 * \brief Applies an version of the median filter optimized for binary images.
 *
 * This filter was contributed by Bjorn Hanch Sollie after identifying that 
 * the generic Median filter performed unecessary operations when the input 
 * image is binary.
 * 
 * This filter Computes an image where a given pixel is the median value 
 * of the pixels in a neighborhood about the corresponding input pixel.
 * For the case of binary images the median can be obtained by simply conting
 * the neigbors that are foreground.
 *
 * A median filter is one of the family of nonlinear filters.  It is
 * used to smooth an image without being biased by outliers or shot noise.
 *
 * \sa Image
 * \sa Neighborhood
 * \sa NeighborhoodOperator
 * \sa NeighborhoodIterator
 * 
 * \ingroup IntensityImageFilters
 */
template <class TInputImage, class TOutputImage>
class ITK_EXPORT BinaryMedianImageFilter :
    public ImageToImageFilter< TInputImage, TOutputImage >
{
public:
  /** Extract dimension from input and output image. */
  itkStaticConstMacro(InputImageDimension, unsigned int,
                      TInputImage::ImageDimension);
  itkStaticConstMacro(OutputImageDimension, unsigned int,
                      TOutputImage::ImageDimension);

  /** Convenient typedefs for simplifying declarations. */
  typedef TInputImage  InputImageType;
  typedef TOutputImage OutputImageType;

  /** Standard class typedefs. */
  typedef BinaryMedianImageFilter                              Self;
  typedef ImageToImageFilter< InputImageType, OutputImageType> 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(BinaryMedianImageFilter, ImageToImageFilter);
  
  /** Image typedef support. */
  typedef typename InputImageType::PixelType  InputPixelType;
  typedef typename OutputImageType::PixelType OutputPixelType;

  typedef typename InputImageType::RegionType  InputImageRegionType;
  typedef typename OutputImageType::RegionType OutputImageRegionType;

  typedef typename InputImageType::SizeType InputSizeType;

  /** Set the radius of the neighborhood used to compute the median. */
  itkSetMacro(Radius, InputSizeType);

  /** Get the radius of the neighborhood used to compute the median */
  itkGetConstReferenceMacro(Radius, InputSizeType);
  
  /** Set the value associated with the Foreground (or the object) on 
      the binary input image and the Background . */
  itkSetMacro(BackgroundValue, InputPixelType);
  itkSetMacro(ForegroundValue, InputPixelType);

  /** Get the value associated with the Foreground (or the object) on the 
      binary input image and the Background . */
  itkGetConstReferenceMacro(BackgroundValue, InputPixelType);
  itkGetConstReferenceMacro(ForegroundValue, InputPixelType);
 

  /** BinaryMedianImageFilter needs a larger input requested region than
   * the output requested region.  As such, BinaryMedianImageFilter needs
   * to provide an implementation for GenerateInputRequestedRegion()
   * in order to inform the pipeline execution model.
   *
   * \sa ImageToImageFilter::GenerateInputRequestedRegion() */
  virtual void GenerateInputRequestedRegion() throw(InvalidRequestedRegionError);

#ifdef ITK_USE_CONCEPT_CHECKING
  /** Begin concept checking */
  itkConceptMacro(InputEqualityComparableCheck,
    (Concept::EqualityComparable<typename TInputImage::PixelType>));
  itkConceptMacro(InputConvertibleToOutputCheck,
    (Concept::Convertible<typename TInputImage::PixelType,
                          typename TOutputImage::PixelType>));
  itkConceptMacro(SameDimensionCheck,
    (Concept::SameDimension<InputImageDimension, OutputImageDimension>));
  itkConceptMacro(InputOStreamWritableCheck,
    (Concept::OStreamWritable<typename TInputImage::PixelType>));
  /** End concept checking */
#endif

protected:
  BinaryMedianImageFilter();
  virtual ~BinaryMedianImageFilter() {}
  void PrintSelf(std::ostream& os, Indent indent) const;

  /** BinaryMedianImageFilter 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 OutputImageRegionType& outputRegionForThread,
                            int threadId );

private:
  BinaryMedianImageFilter(const Self&); //purposely not implemented
  void operator=(const Self&); //purposely not implemented

  InputSizeType m_Radius;

  InputPixelType     m_ForegroundValue;
  InputPixelType     m_BackgroundValue;

};
  
} // end namespace itk

#ifndef ITK_MANUAL_INSTANTIATION
#include "itkBinaryMedianImageFilter.txx"
#endif

#endif
