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

  Program:   Insight Segmentation & Registration Toolkit
  Module:    $RCSfile: itkSignedDanielssonDistanceMapImageFilter.h,v $
  Language:  C++
  Date:      $Date: 2006/03/30 15:36:25 $
  Version:   $Revision: 1.4 $

  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 __itkSignedDanielssonDistanceMapImageFilter_h
#define __itkSignedDanielssonDistanceMapImageFilter_h

#include <itkImageToImageFilter.h>
#include <itkDanielssonDistanceMapImageFilter.h>
#include "itkSubtractImageFilter.h"


//Simple functor to invert an image for Outside Danielsson distance map
namespace itk
{
  namespace Functor
    {
    template <class InputPixelType> class InvertIntensityFunctor
    {
    public:
      InputPixelType operator()( InputPixelType input )
        {
        if (input)
          {
          return NumericTraits<InputPixelType>::Zero;
          }
        else
          {
          return NumericTraits<InputPixelType>::One;
          }
        }
    };
  }
}


namespace itk
{

/** \class SignedDanielssonDistanceMapImageFilter
*
* This class is parametrized over the type of the input image
* and the type of the output image.
*
* This filter computes the distance map of the input image 
* as an approximation with pixel accuracy to the Euclidean distance.
*
* For purposes of evaluating the signed distance map, the input is assumed 
* to be binary composed of pixels with value 0 and non-zero. 
*
* The inside is considered as having negative distances. Outside is treated
* as having positive distances. To change the convention, 
* use the InsideIsPositive(bool) function.
*
* As a convention, the distance is evaluated from the boundary of the ON pixels.
*
* The filter returns
* - A signed distance map with the approximation to the euclidean distance.
* - A voronoi partition. (See itkDanielssonDistanceMapImageFilter) 
* - A vector map containing the component of the vector relating
*   the current pixel with the closest point of the closest object
*   to this pixel. Given that the components of the distance are
*   computed in "pixels", the vector is represented by an
*   itk::Offset.  That is, physical coordinates are not used.
*   (See itkDanielssonDistanceMapImageFilter)
*   
* This filter internally uses the DanielssonDistanceMap filter.
* This filter is N-dimensional.
* 
* \sa itkDanielssonDistanceMapImageFilter
*
* \ingroup ImageFeatureExtraction 
*
*/

template <class TInputImage,class TOutputImage>
class ITK_EXPORT SignedDanielssonDistanceMapImageFilter :
    public ImageToImageFilter<TInputImage,TOutputImage>
{
public:
  /** Standard class typedefs. */
  typedef SignedDanielssonDistanceMapImageFilter    Self;
  typedef ImageToImageFilter<TInputImage,TOutputImage> 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( SignedDanielssonDistanceMapImageFilter, ImageToImageFilter );

  /** Type for input image. */
  typedef   TInputImage       InputImageType;

  /** Type for two of the three output images: the VoronoiMap and the
   * DistanceMap.  */
  typedef   TOutputImage      OutputImageType;

  /** Type for the region of the input image. */
  typedef typename InputImageType::RegionType   RegionType;

  /** Type for the index of the input image. */
  typedef typename RegionType::IndexType  IndexType;

  /** Type for the index of the input image. */
  typedef typename InputImageType::OffsetType  OffsetType;

    /** Type for the pixel type of the input image. */
  typedef typename InputImageType::PixelType  PixelType;

  /** Type for the size of the input image. */
  typedef typename RegionType::SizeType   SizeType;
  
  /** The dimension of the input image. */
  itkStaticConstMacro(InputImageDimension, unsigned int,
                      InputImageType::ImageDimension);

  /** Pointer Type for the vector distance image */
  typedef Image< OffsetType,
                 itkGetStaticConstMacro(InputImageDimension)> VectorImageType;

  /** Pointer Type for input image. */
  typedef typename InputImageType::ConstPointer InputImagePointer;

  /** Pointer Type for the output image. */
  typedef typename OutputImageType::Pointer OutputImagePointer;

  /** Pointer Type for the vector distance image. */
  typedef typename VectorImageType::Pointer VectorImagePointer;

  /** Set if the distance should be squared. */
  itkSetMacro( SquaredDistance, bool );

  /** Get the distance squared. */
  itkGetConstReferenceMacro( SquaredDistance, bool );

  /** Set On/Off if the distance is squared. */
  itkBooleanMacro( SquaredDistance );

  /** Set if image spacing should be used in computing distances. */
  itkSetMacro( UseImageSpacing, bool );

  /** Get whether spacing is used. */
  itkGetConstReferenceMacro( UseImageSpacing, bool );

  /** Set On/Off whether spacing is used. */
  itkBooleanMacro( UseImageSpacing );

  /** Set if the inside represents positive values in the signed distance
   *  map. By convention ON pixels are treated as inside pixels.           */
  itkSetMacro( InsideIsPositive, bool );

  /** Get if the inside represents positive values in the signed distance map. 
   *  See GetInsideIsPositive()  */
  itkGetConstReferenceMacro( InsideIsPositive, bool );

    /** Set if the inside represents positive values in the signed distance
     * map. By convention ON pixels are treated as inside pixels. Default is 
     * true.                             */
  itkBooleanMacro( InsideIsPositive );
  
  /** Get Voronoi Map
   * This map shows for each pixel what object is closest to it. 
   * Each object should be labeled by a number (larger than 0), 
   * so the map has a value for each pixel corresponding to the label 
   * of the closest object.  */
  OutputImageType * GetVoronoiMap(void);

  /** Get Distance map image.  The distance map is shown as a gray
   * value image depending on the pixel type of the output image.
   * Regarding the source image, background should be dark (gray value
   * = 0) and object should have a gray value larger than 0.  The
   * minimal distance is calculated on the object frontier, and the
   * output image gives for each pixel its minimal distance from the
   * object (if there is more than one object the closest object is
   * considered). */
  OutputImageType * GetDistanceMap(void);

  /** Get vector field of distances. */
  VectorImageType * GetVectorDistanceMap(void);

#ifdef ITK_USE_CONCEPT_CHECKING
  /** Begin concept checking */
  itkConceptMacro(IntConvertibleToInputCheck,
                  (Concept::Convertible<int, PixelType>));
  itkConceptMacro(InputHasNumericTraitsCheck,
                  (Concept::HasNumericTraits<PixelType>));
  /** End concept checking */
#endif

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

  /** Compute Danielsson distance map and Voronoi Map. */
  void GenerateData();  
  
private:   
  SignedDanielssonDistanceMapImageFilter(const Self&); //purposely not implemented
  void operator=(const Self&); //purposely not implemented

  bool                  m_SquaredDistance;
  bool                  m_UseImageSpacing;
  bool                  m_InsideIsPositive;   // ON is treated as inside pixels
}; // end of SignedDanielssonDistanceMapImageFilter class

} //end namespace itk


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

#endif
