itkQuadEdgeMeshDiscreteGaussianCurvatureEstimator.h

Go to the documentation of this file.

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

  Program:   Insight Segmentation & Registration Toolkit
  Module:    $RCSfile: itkQuadEdgeMeshDiscreteGaussianCurvatureEstimator.h,v $
  Language:  C++
  Date:      $Date: 2008-10-01 21:40:25 $
  Version:   $Revision: 1.3 $

  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 __itkQuadEdgeMeshDiscreteGaussianCurvatureEstimator_h
#define __itkQuadEdgeMeshDiscreteGaussianCurvatureEstimator_h

#include "itkQuadEdgeMeshDiscreteCurvatureEstimator.h"
#include <vnl/vnl_math.h>

//#include "itkTriangleHelper.h"

namespace itk
{
template< class TInputMesh, class TOutputMesh >
class QuadEdgeMeshDiscreteGaussianCurvatureEstimator :
  public QuadEdgeMeshDiscreteCurvatureEstimator< TInputMesh, TOutputMesh >
{
public:
  typedef QuadEdgeMeshDiscreteGaussianCurvatureEstimator        Self;
  typedef SmartPointer< Self >                                  Pointer;
  typedef SmartPointer< const Self >                            ConstPointer;
  typedef QuadEdgeMeshDiscreteCurvatureEstimator< 
    TInputMesh, TOutputMesh >                                   Superclass;

  typedef typename Superclass::InputMeshType                    InputMeshType;
  typedef typename Superclass::InputMeshPointer                 InputMeshPointer;

  typedef typename Superclass::OutputMeshType                   OutputMeshType;
  typedef typename Superclass::OutputMeshPointer                OutputMeshPointer;
  typedef typename Superclass::OutputPointsContainerPointer     OutputPointsContainerPointer;
  typedef typename Superclass::OutputPointsContainerIterator    OutputPointsContainerIterator;
  typedef typename Superclass::OutputPointType                  OutputPointType;
  typedef typename Superclass::OutputVectorType                 OutputVectorType;
  typedef typename Superclass::OutputCoordType                  OutputCoordType;
  typedef typename Superclass::OutputPointIdentifier            OutputPointIdentifier;
  typedef typename Superclass::OutputCellIdentifier             OutputCellIdentifier;
  typedef typename Superclass::OutputQEType                     OutputQEType;
  typedef typename Superclass::OutputMeshTraits                 OutputMeshTraits;
  typedef typename Superclass::OutputCurvatureType              OutputCurvatureType;
  typedef typename Superclass::TriangleType                     TriangleType;
  
  itkTypeMacro( QuadEdgeMeshDiscreteGaussianCurvatureEstimator, QuadEdgeMeshDiscreteCurvatureEstimator );

  itkNewMacro( Self );

protected:
  QuadEdgeMeshDiscreteGaussianCurvatureEstimator() {}
  ~QuadEdgeMeshDiscreteGaussianCurvatureEstimator() {}

  virtual OutputCurvatureType EstimateCurvature( const OutputPointType& iP )
    {
    OutputMeshPointer output = this->GetOutput();

    OutputQEType* qe = iP.GetEdge( );

    if( qe != 0 )
      {
      OutputQEType* qe_it = qe;
      OutputQEType* qe_it2;

      OutputPointType q0, q1;

      OutputCurvatureType sum_theta = 0.;
      OutputCurvatureType area = 0.;

      do
        {
        // cell_id = qe_it->GetLeft();
        qe_it2 = qe_it->GetOnext();
        q0 = output->GetPoint( qe_it->GetDestination() );
        q1 = output->GetPoint( qe_it2->GetDestination() );

        // Compute Angle;
        sum_theta += static_cast< OutputCurvatureType >(
              TriangleType::ComputeAngle( q0, iP, q1 ) );
        area += ComputeMixedArea( qe_it, qe_it2 );
        qe_it = qe_it2;
        } while( qe_it != qe );

      return ( 2.0 * vnl_math::pi - sum_theta ) / area;

      }

    return 0.;
  
    }

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

};

}

#endif