itkCannyEdgeDetectionImageFilter.h

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

  Program:   Insight Segmentation & Registration Toolkit
  Module:    $RCSfile: itkCannyEdgeDetectionImageFilter.h,v $
  Language:  C++
  Date:      $Date: 2002/12/17 17:50:35 $
  Version:   $Revision: 1.10 $

  Copyright (c) 2002 Insight 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 __itkCannyEdgeDetectionImageFilter_h
#define __itkCannyEdgeDetectionImageFilter_h

#include "itkImageToImageFilter.h"
#include "itkImage.h"
#include "itkConstNeighborhoodIterator.h"
#include "itkZeroFluxNeumannBoundaryCondition.h"
#include "itkMultiThreader.h"
#include "itkDerivativeOperator.h"

namespace itk
{
template<class TInputImage, class TOutputImage>
class ITK_EXPORT CannyEdgeDetectionImageFilter
  : public ImageToImageFilter<TInputImage, TOutputImage>
{
public:
  typedef CannyEdgeDetectionImageFilter    Self;
  typedef ImageToImageFilter<TInputImage, TOutputImage> Superclass;
   
  typedef TInputImage  InputImageType;
  typedef TOutputImage OutputImageType;
      
  typedef SmartPointer<Self>  Pointer;
  typedef SmartPointer<const Self>  ConstPointer;

  typedef typename TInputImage::PixelType  InputImagePixelType;
  typedef typename TOutputImage::PixelType  OutputImagePixelType;

  typedef ZeroFluxNeumannBoundaryCondition<OutputImageType>
  DefaultBoundaryConditionType;

  typedef ConstNeighborhoodIterator<OutputImageType,
    DefaultBoundaryConditionType> NeighborhoodType;

  itkNewMacro(Self);  
    
  typedef typename TOutputImage::RegionType OutputImageRegionType;
    
  itkTypeMacro(CannyEdgeDetectionImageFilter, ImageToImageFilter);
  
  itkStaticConstMacro(ImageDimension, unsigned int,
                      TInputImage::ImageDimension);
  
  itkSetVectorMacro(Variance, double, ImageDimension); 
  itkGetVectorMacro(Variance, const double, ImageDimension); 
  itkSetVectorMacro(MaximumError, double, ImageDimension); 
  itkGetVectorMacro(MaximumError, const double, ImageDimension);
  
  void SetVariance(const double v)
    {
      double vArray[ImageDimension];
      for (unsigned int i = 0; i<ImageDimension; ++i) { vArray[i] = v; }
      this->SetVariance(vArray);
    }
  
  void SetMaximumError(const double v)
    {
      double vArray[ImageDimension];
      for (unsigned int i = 0; i<ImageDimension; ++i) { vArray[i] = v; }
      this->SetMaximumError(vArray);
    }
  
  /* Set the Threshold value for detected edges. */
  itkSetMacro(Threshold, OutputImagePixelType );
  itkGetMacro(Threshold, OutputImagePixelType);

    /* Set the Thresholdvalue for detected edges. */
  itkSetMacro(OutsideValue, OutputImagePixelType);
  itkGetMacro(OutsideValue, OutputImagePixelType);
  
  virtual void GenerateInputRequestedRegion() throw(InvalidRequestedRegionError);

protected:
  CannyEdgeDetectionImageFilter();
  CannyEdgeDetectionImageFilter(const Self&) {}
  void PrintSelf(std::ostream& os, Indent indent) const;

  void GenerateData();

private:
  virtual ~CannyEdgeDetectionImageFilter(){};

  struct CannyThreadStruct
  {
    CannyEdgeDetectionImageFilter *Filter;
  };

  void AllocateUpdateBuffer();


  void Compute2ndDerivative();

  //  virtual
  //  int SplitUpdateContainer(int i, int num, ThreadRegionType& splitRegion);

  void ThreadedCompute2ndDerivative(const OutputImageRegionType&
                                    outputRegionForThread, int threadId);

  static ITK_THREAD_RETURN_TYPE
      Compute2ndDerivativeThreaderCallback( void * arg );

  OutputImagePixelType ComputeCannyEdge(const NeighborhoodType &it,
                                        void *globalData );

  void Compute2ndDerivativePos();

  void ThreadedCompute2ndDerivativePos(const OutputImageRegionType&
                                       outputRegionForThread, int threadId);

  static ITK_THREAD_RETURN_TYPE
  Compute2ndDerivativePosThreaderCallback( void *arg );

  double m_Variance[ImageDimension];

  double m_MaximumError[ImageDimension];  

  OutputImagePixelType m_Threshold;

  OutputImagePixelType m_OutsideValue;

  typename OutputImageType::Pointer  m_UpdateBuffer;
  typename OutputImageType::Pointer  m_UpdateBuffer1;

  DerivativeOperator<OutputImagePixelType,itkGetStaticConstMacro(ImageDimension)>
    m_ComputeCannyEdge1stDerivativeOper;
  DerivativeOperator<OutputImagePixelType,itkGetStaticConstMacro(ImageDimension)>
    m_ComputeCannyEdge2ndDerivativeOper;

  std::slice  m_ComputeCannyEdgeSlice[ImageDimension];

  unsigned long m_Stride[ImageDimension];
  unsigned long m_Center;
};

} //end of namespace itk

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

---