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

  Program:   Insight Segmentation & Registration Toolkit
  Module:    $RCSfile: itkBinaryErodeImageFilter.h,v $
  Language:  C++
  Date:      $Date: 2007-09-12 09:20:29 $
  Version:   $Revision: 1.20 $

  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 __itkBinaryErodeImageFilter_h
#define __itkBinaryErodeImageFilter_h

#include <vector>
#include <queue>
#include "itkBinaryMorphologyImageFilter.h"
#include "itkImage.h"
#include "itkNumericTraits.h"
#include "itkNeighborhoodIterator.h"
#include "itkConstNeighborhoodIterator.h"
#include "itkNeighborhood.h"
#include "itkImageBoundaryCondition.h"
#include "itkImageRegionIterator.h"
#include "itkConceptChecking.h"

namespace itk
{
/**
 * \class BinaryErodeImageFilter
 * \brief Fast binary erosion
 *
 * BinaryErodeImageFilter is a binary erosion
 * morphologic operation. This implementation is based on the papers:
 *
 * L.Vincent "Morphological transformations of binary images with
 * arbitrary structuring elements", and
 *
 * N.Nikopoulos et al. "An efficient algorithm for 3d binary
 * morphological transformations with 3d structuring elements 
 * for arbitrary size and shape". IEEE Transactions on Image
 * Processing. Vol. 9. No. 3. 2000. pp. 283-286.
 *
 * Gray scale images can be processed as binary images by selecting a
 * "ErodeValue".  Pixel values matching the dilate value are
 * considered the "foreground" and all other pixels are
 * "background". This is useful in processing segmented images where
 * all pixels in segment #1 have value 1 and pixels in segment #2 have
 * value 2, etc. A particular "segment number" can be processed.
 * ErodeValue defaults to the maximum possible value of the
 * PixelType. The eroded pixels will receive the BackgroundValue
 * (defaults to 0).
 *
 * The structuring element is assumed to be composed of binary values
 * (zero or one). Only elements of the structuring element having
 * values > 0 are candidates for affecting the center pixel.  A
 * reasonable choice of structuring element is
 * itk::BinaryBallStructuringElement.
 *
 * \sa ImageToImageFilter BinaryDilateImageFilter BinaryMorphologyImageFilter
 */
template <class TInputImage, class TOutputImage, class TKernel>
class ITK_EXPORT BinaryErodeImageFilter :
    public BinaryMorphologyImageFilter< TInputImage, TOutputImage, TKernel >
{
public:
  /** Extract dimension from input and output image. */
  itkStaticConstMacro(InputImageDimension, unsigned int,
                      TInputImage::ImageDimension);
  itkStaticConstMacro(OutputImageDimension, unsigned int,
                      TOutputImage::ImageDimension);

  /** Extract the dimension of the kernel */
  itkStaticConstMacro(KernelDimension, unsigned int,
                      TKernel::NeighborhoodDimension);
  
  /** Convenient typedefs for simplifying declarations. */
  typedef TInputImage  InputImageType;
  typedef TOutputImage OutputImageType;
  typedef TKernel      KernelType;
  

  /** Standard class typedefs. */
  typedef BinaryErodeImageFilter    Self;
  typedef BinaryMorphologyImageFilter<InputImageType, OutputImageType,
    KernelType> 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(BinaryErodeImageFilter, BinaryMorphologyImageFilter);

  /** Kernel (structuring element) iterator. */
  typedef typename KernelType::ConstIterator KernelIteratorType;

  /** Image typedef support. */
  typedef typename InputImageType::PixelType               InputPixelType;
  typedef typename OutputImageType::PixelType              OutputPixelType;
  typedef typename NumericTraits<InputPixelType>::RealType InputRealType;
  typedef typename InputImageType::OffsetType              OffsetType;
  typedef typename InputImageType::IndexType               IndexType;

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

  /** Set the value in the image to consider as "foreground". Defaults to
   * maximum value of PixelType. This is an alias to the
   * ForegroundValue in the superclass. */
  void SetErodeValue(const InputPixelType& value)
    { this->SetForegroundValue( value ); }

  /** Get the value in the image considered as "foreground". Defaults to
   * maximum value of PixelType. This is an alias to the
   * ForegroundValue in the superclass. */
  InputPixelType GetErodeValue() const
    { return this->GetForegroundValue(); }

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

  void GenerateData();

  // type inherited from the superclass
  typedef typename Superclass::NeighborIndexContainer NeighborIndexContainer;

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

};

} // end namespace itk

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

#endif
