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
|
/*=========================================================================
Program: Insight Segmentation & Registration Toolkit
Module: $RCSfile: itkCentralDifferenceImageFunction.txx,v $
Language: C++
Date: $Date: 2008-02-04 12:34:11 $
Version: $Revision: 1.32 $
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 __itkCentralDifferenceImageFunction_txx
#define __itkCentralDifferenceImageFunction_txx
#include "itkCentralDifferenceImageFunction.h"
namespace itk
{
/**
* Constructor
*/
template <class TInputImage, class TCoordRep>
CentralDifferenceImageFunction<TInputImage,TCoordRep>
::CentralDifferenceImageFunction()
{
this->m_UseImageDirection = false;
}
/**
*
*/
template <class TInputImage, class TCoordRep>
void
CentralDifferenceImageFunction<TInputImage,TCoordRep>
::PrintSelf(std::ostream& os, Indent indent) const
{
this->Superclass::PrintSelf(os,indent);
os << indent << "UseImageDirection = " << this->m_UseImageDirection << std::endl;
}
/**
*
*/
template <class TInputImage, class TCoordRep>
typename CentralDifferenceImageFunction<TInputImage,TCoordRep>::OutputType
CentralDifferenceImageFunction<TInputImage,TCoordRep>
::EvaluateAtIndex( const IndexType& index ) const
{
OutputType derivative;
derivative.Fill( 0.0 );
IndexType neighIndex = index;
const InputImageType * inputImage = this->GetInputImage();
const typename InputImageType::RegionType region =
inputImage->GetBufferedRegion();
const typename InputImageType::SizeType& size = region.GetSize();
const typename InputImageType::IndexType& start = region.GetIndex();
for ( unsigned int dim = 0; dim < TInputImage::ImageDimension; dim++ )
{
// bounds checking
if( index[dim] < static_cast<long>(start[dim]) + 1 ||
index[dim] > (start[dim] + static_cast<long>(size[dim]) - 2 ) )
{
derivative[dim] = 0.0;
continue;
}
// compute derivative
neighIndex[dim] += 1;
derivative[dim] = inputImage->GetPixel( neighIndex );
neighIndex[dim] -= 2;
derivative[dim] -= inputImage->GetPixel( neighIndex );
derivative[dim] *= 0.5 / inputImage->GetSpacing()[dim];
neighIndex[dim] += 1;
}
#ifdef ITK_USE_ORIENTED_IMAGE_DIRECTION
if( this->m_UseImageDirection )
{
OutputType orientedDerivative;
inputImage->TransformLocalVectorToPhysicalVector( derivative, orientedDerivative );
return orientedDerivative;
}
#endif
return ( derivative );
}
} // end namespace itk
#endif
|
