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/*========================================================================= |
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Program: Insight Segmentation & Registration Toolkit |
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Module: $RCSfile: itkLaplacianOperator.h.html,v $ |
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Language: C++ |
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Date: $Date: 2006/01/17 19:15:40 $ |
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Version: $Revision: 1.4 $ |
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Copyright (c) Insight Software Consortium. All rights reserved. |
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See ITKCopyright.txt or http://www.itk.org/HTML/Copyright.htm for details. |
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This software is distributed WITHOUT ANY WARRANTY; without even |
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the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR |
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PURPOSE. See the above copyright notices for more information. |
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=========================================================================*/ |
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#ifndef __itkLaplacianOperator_h |
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#define __itkLaplacianOperator_h |
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#include "itkExceptionObject.h" |
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#include "itkNeighborhoodOperator.h" |
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namespace itk { |
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/** |
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* \class LaplacianOperator |
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* |
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* A NeighborhoodOperator for use in calculating the Laplacian at a pixel. |
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* The LaplacianOperator's coefficients are a tightest-fitting convolution |
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* kernel. |
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* |
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* For example, the simplest Laplacian Operator for 2D has the form: |
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* \code |
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* 0 1 0 |
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* 1 -4 1 |
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* 0 1 0 |
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* \endcode |
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* |
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* \par |
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* The LaplacianOperator is a non-directional NeighborhoodOperator that |
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* should be applied to a Neighborhood or NeighborhoodIterator using an inner |
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* product method (itkNeighborhoodInnerProduct). To initialize the operator, you |
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* need call CreateOperator() before using it. |
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* |
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* \par |
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* By default the operator will be created for an isotropic image, but you can |
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* modify the operator to handle different pixel spacings by calling |
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* SetDerivativeScalings. The argument to SetDerivativeScalings is an array |
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* of doubles that is of length VDimension (the dimensionality of the image). |
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* Make sure to use 1/pixel_spacing to properly scale derivatives. |
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* |
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* \sa NeighborhoodOperator |
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* \sa Neighborhood |
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* \ingroup Operators */ |
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template<class TPixel, unsigned int VDimension=2, |
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class TAllocator = NeighborhoodAllocator<TPixel> > |
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class ITK_EXPORT LaplacianOperator |
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**: public NeighborhoodOperator<TPixel, VDimension, TAllocator> |
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{ |
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public: |
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/** Standard "Self" typedef support. */ |
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typedef LaplacianOperator Self; |
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/** Standard "Superclass" typedef. */ |
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typedef NeighborhoodOperator<TPixel, VDimension, TAllocator> Superclass; |
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typedef typename Superclass::PixelType PixelType; |
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typedef typename Superclass::SizeType SizeType; |
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*/** Default constructor */ |
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LaplacianOperator() |
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**{ |
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for (unsigned i = 0; i < VDimension; ++i) |
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{ |
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m_DerivativeScalings[i] = 1.0; |
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} |
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} |
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/** Copy constructor */ |
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LaplacianOperator(const Self& other) |
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: NeighborhoodOperator<TPixel, VDimension, TAllocator>(other) |
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**{ |
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for (unsigned i = 0; i < VDimension; ++i) |
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{ |
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m_DerivativeScalings[i] = other.m_DerivativeScalings[i]; |
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} |
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**} |
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/** This function is called to create the operator */ |
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void CreateOperator(); |
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/** Assignment operator */ |
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Self &operator=(const Self& other) |
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**{ |
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Superclass::operator=(other); |
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return *this; |
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**} |
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/** Prints some debugging information */ |
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virtual void PrintSelf(std::ostream &os, Indent i) const |
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**{ |
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os << i << "LaplacianOperator { this=" << this |
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*******<< "}" << std::endl; |
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Superclass::PrintSelf(os, i.GetNextIndent()); |
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**} |
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/** Sets the weights that are applied to the derivative in each axial |
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* direction when the kernel is computed. These weights are all 1.0 by |
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* default. This method must be called BEFORE CreateOperator */ |
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void SetDerivativeScalings( const double *s ); |
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protected: |
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/** Typedef support for coefficient vector type. Necessary to |
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* work around compiler bug on VC++. */ |
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typedef typename Superclass::CoefficientVector CoefficientVector; |
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/** Calculates operator coefficients. */ |
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CoefficientVector GenerateCoefficients(); |
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/** Arranges coefficients spatially in the memory buffer, default |
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* function was NOT used. */ |
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void Fill(const CoefficientVector &); |
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private: |
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/** Weights applied to derivatives in each axial direction */ |
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double m_DerivativeScalings[VDimension]; |
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}; |
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} // namespace itk |
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#ifndef ITK_MANUAL_INSTANTIATION |
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#include "itkLaplacianOperator.txx" |
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#endif |
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#endif |
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EOF |
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EOF,EML |
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