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
175
176
177
178
179
180
181
182
183
184
185
186
187
|
/*=========================================================================
*
* Copyright NumFOCUS
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* https://www.apache.org/licenses/LICENSE-2.0.txt
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*=========================================================================*/
#ifndef itkMahalanobisDistanceThresholdImageFunction_h
#define itkMahalanobisDistanceThresholdImageFunction_h
#include "itkImageFunction.h"
#include "itkMahalanobisDistanceMembershipFunction.h"
namespace itk
{
/**
* \class MahalanobisDistanceThresholdImageFunction
* \brief Returns true if the pixel value of a vector image has a
* Mahalanobis distance below the value specified by the threshold.
*
* This ImageFunction returns true if the pixel value of a vector image has a
* Mahalanobis distance below the value specified by the threshold. The
* Mahalanobis distance is computed with the
* MahalanobisDistanceMembershipFunction class which has to be initialized with
* a mean and covariance. This class is intended to be used only
* with images whose pixel type is a vector (array).
*
* The input image is set via method SetInputImage().
*
* Methods Evaluate, EvaluateAtIndex and EvaluateAtContinuousIndex respectively
* evaluate the function at an geometric point, image index and continuous
* image index.
*
* \ingroup ImageFunctions
*
*
* \ingroup ITKImageFunction
*/
template <typename TInputImage, typename TCoordRep = float>
class ITK_TEMPLATE_EXPORT MahalanobisDistanceThresholdImageFunction : public ImageFunction<TInputImage, bool, TCoordRep>
{
public:
ITK_DISALLOW_COPY_AND_MOVE(MahalanobisDistanceThresholdImageFunction);
/** Standard class type aliases. */
using Self = MahalanobisDistanceThresholdImageFunction;
using Superclass = ImageFunction<TInputImage, bool, TCoordRep>;
using Pointer = SmartPointer<Self>;
using ConstPointer = SmartPointer<const Self>;
/** \see LightObject::GetNameOfClass() */
itkOverrideGetNameOfClassMacro(MahalanobisDistanceThresholdImageFunction);
/** Method for creation through the object factory. */
itkNewMacro(Self);
/** InputImageType type alias support */
using typename Superclass::InputImageType;
/** Typedef to describe the type of pixel. */
using PixelType = typename TInputImage::PixelType;
/** Dimension underlying input image. */
static constexpr unsigned int ImageDimension = Superclass::ImageDimension;
/** Point type alias support */
using typename Superclass::PointType;
/** Index type alias support */
using typename Superclass::IndexType;
/** ContinuousIndex type alias support */
using typename Superclass::ContinuousIndexType;
/** Type used to represent the Covariance matrix of the vector population. */
using CovarianceMatrixType = vnl_matrix<double>;
/** Type used to represent the Mean Vector of the vector population. */
using MeanVectorType = vnl_vector<double>;
/** BinaryThreshold the image at a point position
*
* Returns true if the image intensity at the specified point position
* satisfies the threshold criteria. The point is assumed to lie within
* the image buffer.
*
* ImageFunction::IsInsideBuffer() can be used to check bounds before
* calling the method. */
bool
Evaluate(const PointType & point) const override;
/** BinaryThreshold the image at a continuous index position
*
* Returns true if the image intensity at the specified point position
* satisfies the threshold criteria. The point is assumed to lie within
* the image buffer.
*
* ImageFunction::IsInsideBuffer() can be used to check bounds before
* calling the method. */
bool
EvaluateAtContinuousIndex(const ContinuousIndexType & index) const override;
/** BinaryThreshold the image at an index position.
*
* Returns true if the image intensity at the specified point position
* satisfies the threshold criteria. The point is assumed to lie within
* the image buffer.
*
* ImageFunction::IsInsideBuffer() can be used to check bounds before
* calling the method. */
bool
EvaluateAtIndex(const IndexType & index) const override;
/** Returns the actual value of the MahalanobisDistance at that point.
* The point is assumed to lie within the image buffer.
* ImageFunction::IsInsideBuffer() can be used to check bounds before
* calling the method. */
virtual double
EvaluateDistance(const PointType & point) const;
/** Returns the actual value of the MahalanobisDistance at that index.
* The point is assumed to lie within the image buffer.
* ImageFunction::IsInsideBuffer() can be used to check bounds before
* calling the method. */
virtual double
EvaluateDistanceAtIndex(const IndexType & index) const;
/** Get the lower threshold value. */
itkGetConstReferenceMacro(Threshold, double);
itkSetMacro(Threshold, double);
/** Set the mean.
* Set this mean value to the membership function. */
void
SetMean(const MeanVectorType & mean);
/** Get the mean.
* The mean set on the membership function matches this value. */
itkGetConstReferenceMacro(Mean, MeanVectorType);
/** Set the covariance matrix.
* Set this covariance matrix to the membership function. */
void
SetCovariance(const CovarianceMatrixType & covariance);
/** Get the covariance matrix.
* The covariance matrix set on the membership function matches this value. */
itkGetConstReferenceMacro(Covariance, CovarianceMatrixType);
protected:
MahalanobisDistanceThresholdImageFunction();
~MahalanobisDistanceThresholdImageFunction() override = default;
void
PrintSelf(std::ostream & os, Indent indent) const override;
private:
double m_Threshold{};
// This is intended only for Image of Vector pixel type.
using MahalanobisDistanceFunctionType = Statistics::MahalanobisDistanceMembershipFunction<PixelType>;
using MahalanobisDistanceFunctionPointer = typename MahalanobisDistanceFunctionType::Pointer;
MahalanobisDistanceFunctionPointer m_MahalanobisDistanceMembershipFunction{};
// Cached versions of the mean and covariance to manage the
// difference in vector/matrix types between this class and the
// membership function used internally.
MeanVectorType m_Mean{};
CovarianceMatrixType m_Covariance{};
};
} // end namespace itk
#ifndef ITK_MANUAL_INSTANTIATION
# include "itkMahalanobisDistanceThresholdImageFunction.hxx"
#endif
#endif
|
