/usr/include/InsightToolkit/Review/itkOptLinearInterpolateImageFunction.txx is in libinsighttoolkit3-dev 3.20.1+git20120521-6build1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 | /*=========================================================================
Program: Insight Segmentation & Registration Toolkit
Module: itkOptLinearInterpolateImageFunction.txx
Language: C++
Date: $Date$
Version: $Revision$
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 __itkOptLinearInterpolateImageFunction_txx
#define __itkOptLinearInterpolateImageFunction_txx
#include "itkOptLinearInterpolateImageFunction.h"
#include "vnl/vnl_math.h"
namespace itk
{
/**
* Define the number of neighbors
*/
template<class TInputImage, class TCoordRep>
const unsigned long
LinearInterpolateImageFunction< TInputImage, TCoordRep >
::m_Neighbors = 1 << TInputImage::ImageDimension;
/**
* Constructor
*/
template<class TInputImage, class TCoordRep>
LinearInterpolateImageFunction< TInputImage, TCoordRep >
::LinearInterpolateImageFunction()
{
}
template<class TInputImage, class TCoordRep>
LinearInterpolateImageFunction< TInputImage, TCoordRep >
::~LinearInterpolateImageFunction()
{
}
/**
* PrintSelf
*/
template<class TInputImage, class TCoordRep>
void
LinearInterpolateImageFunction< TInputImage, TCoordRep >
::PrintSelf(std::ostream& os, Indent indent) const
{
this->Superclass::PrintSelf(os,indent);
}
/**
* Evaluate at image index position
*/
template<class TInputImage, class TCoordRep>
typename LinearInterpolateImageFunction< TInputImage, TCoordRep >
::OutputType
LinearInterpolateImageFunction< TInputImage, TCoordRep >
::EvaluateUnoptimized( const ContinuousIndexType& index) const
{
unsigned int dim; // index over dimension
/**
* Compute base index = closet index below point
* Compute distance from point to base index
*/
IndexType baseIndex;
double distance[ImageDimension];
for( dim = 0; dim < ImageDimension; dim++ )
{
baseIndex[dim] = Math::Floor<IndexValueType>( index[dim] );
distance[dim] = index[dim] - static_cast< double >( baseIndex[dim] );
}
/**
* Interpolated value is the weighted sum of each of the surrounding
* neighbors. The weight for each neighbor is the fraction overlap
* of the neighbor pixel with respect to a pixel centered on point.
*/
RealType value = NumericTraits<RealType>::Zero;
typedef typename NumericTraits<InputPixelType>::ScalarRealType ScalarRealType;
ScalarRealType totalOverlap = NumericTraits<ScalarRealType>::Zero;
for( unsigned int counter = 0; counter < m_Neighbors; counter++ )
{
double overlap = 1.0; // fraction overlap
unsigned int upper = counter; // each bit indicates upper/lower neighbour
IndexType neighIndex;
// get neighbor index and overlap fraction
for( dim = 0; dim < ImageDimension; dim++ )
{
if ( upper & 1 )
{
neighIndex[dim] = baseIndex[dim] + 1;
#ifdef ITK_USE_CENTERED_PIXEL_COORDINATES_CONSISTENTLY
// Take care of the case where the pixel is just
// in the outer upper boundary of the image grid.
if( neighIndex[dim] > this->m_EndIndex[dim] )
{
neighIndex[dim] = this->m_EndIndex[dim];
}
#endif
overlap *= distance[dim];
}
else
{
neighIndex[dim] = baseIndex[dim];
#ifdef ITK_USE_CENTERED_PIXEL_COORDINATES_CONSISTENTLY
// Take care of the case where the pixel is just
// in the outer lower boundary of the image grid.
if( neighIndex[dim] < this->m_StartIndex[dim] )
{
neighIndex[dim] = this->m_StartIndex[dim];
}
#endif
overlap *= 1.0 - distance[dim];
}
upper >>= 1;
}
// get neighbor value only if overlap is not zero
if( overlap )
{
value += static_cast<RealType>( this->GetInputImage()->GetPixel( neighIndex ) ) * overlap;
totalOverlap += overlap;
}
if( totalOverlap == 1.0 )
{
// finished
break;
}
}
return ( static_cast<OutputType>( value ) );
}
} // end namespace itk
#endif
|