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
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
|
/*=========================================================================
Program: Insight Segmentation & Registration Toolkit
Module: $RCSfile: itkVectorThresholdSegmentationLevelSetFunction.h,v $
Language: C++
Date: $Date: 2003-12-23 18:33:14 $
Version: $Revision: 1.6 $
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 __itkVectorThresholdSegmentationLevelSetFunction_h_
#define __itkVectorThresholdSegmentationLevelSetFunction_h_
#include "itkSegmentationLevelSetFunction.h"
#include "itkNumericTraits.h"
#include "itkMahalanobisDistanceMembershipFunction.h"
namespace itk {
/** \class VectorThresholdSegmentationLevelSetFunction
*
* \brief This function is used in VectorThresholdSegmentationLevelSetImageFilter to
* segment structures in images based on the Mahalanobis distance.
*
* \par CREDITS
* This class was contributed to ITK by Stefan Lindenau
* http://www.itk.org/pipermail/insight-users/2003-December/005969.html
*
* \par SegmentationLevelSetFunction is a subclass of the generic LevelSetFunction.
* It useful for segmentations based on intensity values in an image. It works
* by constructing a speed term (feature image) with positive values inside an
* intensity window (between a low and high threshold) and negative values
* outside that intensity window. The evolving level set front will lock onto
* regions that are at the edges of the intensity window.
*
*
* \par
* Image \f$ f(x) \f$ is thresholded pixel by pixel using threshold \f$T\f$
* according to the following formula.
*
* \par
* \f[
* f(x) = T - MahalanobisDistance(x)
* \f]
*
* \sa SegmentationLevelSetImageFunction
* \sa ThresholdSegmentationLevelSetImageFilter
* \sa MahalanobisDistanceMembershipFunction*/
template <class TImageType, class TFeatureImageType>
class ITK_EXPORT VectorThresholdSegmentationLevelSetFunction
: public SegmentationLevelSetFunction<TImageType, TFeatureImageType>
{
public:
/** Standard class typedefs. */
typedef VectorThresholdSegmentationLevelSetFunction Self;
typedef SegmentationLevelSetFunction<TImageType, TFeatureImageType> Superclass;
typedef SmartPointer<Self> Pointer;
typedef SmartPointer<const Self> ConstPointer;
typedef TFeatureImageType FeatureImageType;
/** Method for creation through the object factory. */
itkNewMacro(Self);
/** Run-time type information (and related methods) */
itkTypeMacro( VectorThresholdSegmentationLevelSetFunction, SegmentationLevelSetFunction );
/** Extract some parameters from the superclass. */
typedef typename Superclass::ImageType ImageType;
typedef typename Superclass::ScalarValueType ScalarValueType;
typedef typename Superclass::FeatureScalarType FeatureScalarType;
typedef typename Superclass::RadiusType RadiusType;
/** Extract some parameters from the superclass. */
itkStaticConstMacro(ImageDimension, unsigned int,
Superclass::ImageDimension);
/** Extract the number of components in the vector pixel type . */
typedef typename FeatureImageType::PixelType FeatureImagePixelType;
itkStaticConstMacro(NumberOfComponents, unsigned int,
FeatureImagePixelType::Dimension);
typedef Statistics::MahalanobisDistanceMembershipFunction<FeatureScalarType> MahalanobisFunctionType;
typedef typename MahalanobisFunctionType::Pointer MahalanobisFunctionPointer;
typedef typename MahalanobisFunctionType::MeanVectorType MeanVectorType;
typedef typename MahalanobisFunctionType::CovarianceMatrixType CovarianceMatrixType;
/** Set/Get mean and covariance */
void SetMean(const MeanVectorType &mean)
{ m_Mahalanobis->SetMean(mean); }
const MeanVectorType & GetMean() const
{ return m_Mahalanobis->GetMean(); }
void SetCovariance(const CovarianceMatrixType &cov)
{ m_Mahalanobis->SetCovariance(cov); }
const CovarianceMatrixType & GetCovariance() const
{ return m_Mahalanobis->GetCovariance(); }
/** Set/Get the threshold value for the MahanalobisDistance */
void SetThreshold(ScalarValueType thr)
{
m_Threshold = thr;
}
ScalarValueType GetThreshold()
{
return m_Threshold;
}
virtual void CalculateSpeedImage();
virtual void Initialize(const RadiusType &r)
{
Superclass::Initialize(r);
this->SetAdvectionWeight( NumericTraits<ScalarValueType>::Zero);
this->SetPropagationWeight(-1.0 * NumericTraits<ScalarValueType>::One);
this->SetCurvatureWeight(NumericTraits<ScalarValueType>::One);
}
protected:
VectorThresholdSegmentationLevelSetFunction()
{
MeanVectorType mean( NumberOfComponents );
CovarianceMatrixType covariance( NumberOfComponents, NumberOfComponents );
mean.fill(NumericTraits<ITK_TYPENAME FeatureScalarType::ValueType>::Zero);
covariance.fill(NumericTraits<ITK_TYPENAME FeatureScalarType::ValueType>::Zero);
m_Mahalanobis = MahalanobisFunctionType::New();
m_Mahalanobis->SetMean(mean);
m_Mahalanobis->SetCovariance(covariance);
this->SetAdvectionWeight(0.0);
this->SetPropagationWeight(1.0);
this->SetThreshold(1.8);
}
virtual ~VectorThresholdSegmentationLevelSetFunction(){}
VectorThresholdSegmentationLevelSetFunction(const Self&); //purposely not implemented
void operator=(const Self&); //purposely not implemented
void PrintSelf(std::ostream& os, Indent indent) const
{
Superclass::PrintSelf(os, indent );
os << indent << "MahalanobisFunction: " << m_Mahalanobis << std::endl;
os << indent << "ThresholdValue: " << m_Threshold << std::endl;
}
MahalanobisFunctionPointer m_Mahalanobis;
ScalarValueType m_Threshold;
};
} // end namespace itk
#ifndef ITK_MANUAL_INSTANTIATION
#include "itkVectorThresholdSegmentationLevelSetFunction.txx"
#endif
#endif
|
