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/*========================================================================= |
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Program: Insight Segmentation & Registration Toolkit |
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Module: $RCSfile: itkDerivativeOperator.txx.html,v $ |
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Language: C++ |
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Date: $Date: 2006/01/17 19:15:34 $ |
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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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DEF |
#ifndef _itkDerivativeOperator_txx |
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DEF |
#define _itkDerivativeOperator_txx |
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#include "itkDerivativeOperator.h" |
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#include "itkNumericTraits.h" |
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namespace itk |
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{ |
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template <class TPixel, unsigned int VDimension, class TAllocator> |
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typename DerivativeOperator<TPixel, VDimension, TAllocator> |
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::CoefficientVector |
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DerivativeOperator<TPixel, VDimension, TAllocator> |
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::GenerateCoefficients() |
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{ |
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unsigned int i; |
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unsigned int j; |
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typedef typename NumericTraits<PixelType>::RealType PixelRealType; |
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PixelRealType previous; |
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PixelRealType next; |
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const unsigned int w = 2*((m_Order + 1)/2) + 1; |
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CoefficientVector coeff(w); |
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coeff[w/2] = 1.0; |
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for (i = 0; i < m_Order/2; i++) |
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{ |
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previous = coeff[1] - 2 * coeff[0]; |
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for (j = 1; j < w - 1; j++) |
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{ |
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next =coeff[j - 1] + coeff[j + 1] - 2*coeff[j]; |
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coeff[j-1] = previous; |
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previous = next; |
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} |
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next = coeff[j - 1] - 2*coeff[j]; |
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coeff[j-1] = previous; |
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coeff[j] = next; |
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} |
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for (i = 0; i < m_Order%2; i++) |
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{ |
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previous = 0.5 * coeff[1]; |
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for (j = 1; j < w - 1; j++) |
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{ |
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next = -0.5*coeff[j - 1] + 0.5*coeff[j + 1]; |
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coeff[j-1] = previous; |
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previous = next; |
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} |
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next = -0.5 * coeff[j - 1]; |
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coeff[j-1] = previous; |
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coeff[j] = next; |
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} |
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return coeff; |
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} |
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} // namespace itk |
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#endif |
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