/*=========================================================================
 *
 *  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 __itkReconstructionByErosionImageFilter_h
#define __itkReconstructionByErosionImageFilter_h

#include "itkReconstructionImageFilter.h"

#include "itkNumericTraits.h"

namespace itk
{
/** \class ReconstructionByErosionImageFilter
 * \brief grayscale reconstruction by erosion of an image
 *
 * Reconstruction by erosion operates on a "marker" image and a "mask"
 * image, and is defined as the erosion of the marker image with
 * respect to the mask image iterated until stability.
 *
 * The marker image must be less than or equal to the mask image
 * (on a pixel by pixel basis).
 *
 * Geodesic morphology is described in Chapter 6.2 of Pierre Soille's
 * book "Morphological Image Analysis: Principles and Applications",
 * Second Edition, Springer, 2003.
 *
 * Algorithm implemented in this filter is based on algorithm described
 * by Kevin Robinson and  Paul F. Whelan in "Efficient Morphological
 * Reconstruction: A Downhill Filter", Pattern Recognition Letters, Volume
 * 25, Issue 15, November 2004, Pages 1759-1767.
 *
 * The algorithm, a description of the transform and some applications
 * can be found in "Morphological Grayscale Reconstruction in Image Analysis:
 * Applications and Efficient Algorithms", Luc Vincent, IEEE Transactions on
 * image processing, Vol. 2, April 1993.
 *
 * \author Richard Beare. Department of Medicine, Monash University,
 * Melbourne, Australia.
 *
 * \sa MorphologyImageFilter, GrayscaleDilateImageFilter, GrayscaleFunctionDilateImageFilter, BinaryDilateImageFilter, ReconstructionByErosionImageFilter,
OpeningByReconstructionImageFilter, ClosingByReconstructionImageFilter, ReconstructionImageFilter
 * \ingroup ImageEnhancement  MathematicalMorphologyImageFilters
 * \ingroup MathematicalMorphologyImageFilters
 * \ingroup ITKMathematicalMorphology
 */

template< typename TInputImage, typename TOutputImage >
class ReconstructionByErosionImageFilter:
  public ReconstructionImageFilter< TInputImage, TOutputImage, std::less< typename TOutputImage::PixelType > >
{
public:
  typedef ReconstructionByErosionImageFilter Self;
  typedef ReconstructionImageFilter<
    TInputImage, TOutputImage, std::less< typename TOutputImage::PixelType > > Superclass;

  typedef SmartPointer< Self >       Pointer;
  typedef SmartPointer< const Self > ConstPointer;

  /** Some convenient typedefs. */
  typedef TInputImage                            MarkerImageType;
  typedef typename MarkerImageType::Pointer      MarkerImagePointer;
  typedef typename MarkerImageType::ConstPointer MarkerImageConstPointer;
  typedef typename MarkerImageType::RegionType   MarkerImageRegionType;
  typedef typename MarkerImageType::PixelType    MarkerImagePixelType;
  typedef TInputImage                            MaskImageType;
  typedef typename MaskImageType::Pointer        MaskImagePointer;
  typedef typename MaskImageType::ConstPointer   MaskImageConstPointer;
  typedef typename MaskImageType::RegionType     MaskImageRegionType;
  typedef typename MaskImageType::PixelType      MaskImagePixelType;
  typedef TOutputImage                           OutputImageType;
  typedef typename OutputImageType::Pointer      OutputImagePointer;
  typedef typename OutputImageType::ConstPointer OutputImageConstPointer;
  typedef typename OutputImageType::RegionType   OutputImageRegionType;
  typedef typename OutputImageType::PixelType    OutputImagePixelType;

  /** ImageDimension constants */
  itkStaticConstMacro(MarkerImageDimension, unsigned int,
                      TInputImage::ImageDimension);
  itkStaticConstMacro(MaskImageDimension, unsigned int,
                      TInputImage::ImageDimension);
  itkStaticConstMacro(OutputImageDimension, unsigned int,
                      TOutputImage::ImageDimension);

  /** Method for creation through the object factory. */
  itkNewMacro(Self);

  /** Runtime information support. */
  itkTypeMacro(ReconstructionByErosionImageFilter,
               ReconstructionImageFilter);

protected:
  ReconstructionByErosionImageFilter()
  {
    this->m_MarkerValue = NumericTraits< typename TOutputImage::PixelType >::max();
  }

  virtual ~ReconstructionByErosionImageFilter() {}

private:
  ReconstructionByErosionImageFilter(const Self &); //purposely not implemented
  void operator=(const Self &);                     //purposely not implemented
};                                                  // end
                                                    //
                                                    //
                                                    //
                                                    //
                                                    // ReconstructionByErosionImageFilter
}

#endif
