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
|
/*=========================================================================
Program: Insight Segmentation & Registration Toolkit
Module: $RCSfile: itkImagePCADecompositionCalculator.txx,v $
Language: C++
Date: $Date: 2005-08-30 00:29:02 $
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 _itkImagePCADecompositionCalculator_txx
#define _itkImagePCADecompositionCalculator_txx
#ifdef _MSC_VER
#pragma warning( disable : 4288 )
#endif
#include "itkImagePCADecompositionCalculator.h"
#include "itkImageRegionConstIterator.h"
namespace itk
{
/*
* Constructor
*/
template<class TInputImage, class TBasisImage>
ImagePCADecompositionCalculator<TInputImage, TBasisImage>
::ImagePCADecompositionCalculator()
{
m_Image = NULL;
m_MeanImage = NULL;
m_BasisMatrixCalculated = false;
}
template<class TInputImage, class TBasisImage>
void
ImagePCADecompositionCalculator<TInputImage, TBasisImage>
::SetBasisImages(const BasisImagePointerVector &v)
{
itkDebugMacro(<< "setting BasisImages");
this->m_BasisMatrixCalculated = false;
// We need this modified setter function so that the calculator
// can cache the basis set between calculations. Note that computing the
// basis matrix from the input images is rather expensive, and the basis
// images are likely to be changed less often than the input images. So
// it makes sense to try to cache the pre-computed matrix.
this->m_BasisImages = v;
this->Modified();
}
/*
* Compute the projection
*/
template<class TInputImage, class TBasisImage>
void
ImagePCADecompositionCalculator<TInputImage, TBasisImage>
::Compute(void)
{
if (!m_BasisMatrixCalculated)
{
this->CalculateBasisMatrix();
}
this->CalculateRecenteredImageAsVector();
m_Projection = m_BasisMatrix * m_ImageAsVector;
}
/*
* Convert a vector of basis images into a matrix. Each image is flattened into 1-D.
*/
template<class TInputImage, class TBasisImage>
void
ImagePCADecompositionCalculator<TInputImage, TBasisImage>
::CalculateBasisMatrix(void) {
m_Size = m_BasisImages[0]->GetRequestedRegion().GetSize();
m_NumPixels = 1;
for( unsigned int i = 0; i < BasisImageDimension; i++ )
{
m_NumPixels *= m_Size[i];
}
m_BasisMatrix = BasisMatrixType(m_BasisImages.size(), m_NumPixels);
int i = 0;
for(typename BasisImagePointerVector::const_iterator basis_it = m_BasisImages.begin();
basis_it != m_BasisImages.end(); ++basis_it)
{
if( (*basis_it)->GetRequestedRegion().GetSize() != m_Size)
{
itkExceptionMacro("All basis images must be the same size!");
}
ImageRegionConstIterator<BasisImageType> image_it(*basis_it,
(*basis_it)->GetRequestedRegion());
int j = 0;
for (image_it.GoToBegin(); !image_it.IsAtEnd(); ++image_it)
{
m_BasisMatrix(i, j++) = image_it.Get();
}
i++;
}
m_BasisMatrixCalculated = true;
m_ImageAsVector.set_size(m_NumPixels);
}
/*
* Convert an image into a 1-D vector, changing the pixel type if necessary.
*/
template<class TInputImage, class TBasisImage>
void
ImagePCADecompositionCalculator<TInputImage, TBasisImage>
::CalculateRecenteredImageAsVector(void) {
if ( m_Image->GetRequestedRegion().GetSize() != m_Size)
{
itkExceptionMacro("Input image must be the same size as the basis images!");
}
ImageRegionConstIterator<InputImageType> image_it(m_Image,
m_Image->GetRequestedRegion());
typename BasisVectorType::iterator vector_it;
for (image_it.GoToBegin(), vector_it = m_ImageAsVector.begin();
!image_it.IsAtEnd(); ++image_it, ++vector_it)
{
*vector_it = static_cast<BasisPixelType> (image_it.Get());
}
if (m_MeanImage)
{
ImageRegionConstIterator<BasisImageType> mimage_it(m_MeanImage,
m_MeanImage->GetRequestedRegion());
for (mimage_it.GoToBegin(), vector_it = m_ImageAsVector.begin();
!mimage_it.IsAtEnd(); ++mimage_it, ++vector_it)
{
*vector_it -= (mimage_it.Get());
}
}
}
template<class TInputImage, class TBasisImage>
void
ImagePCADecompositionCalculator<TInputImage, TBasisImage>
::SetBasisFromModel(ModelPointerType model) {
BasisImagePointerVector images;
unsigned int nImages = model->GetNumberOfPrincipalComponentsRequired();
images.reserve(nImages);
for(int i = 1; i <= nImages; i++)
{
images.push_back(model->GetOutput(i));
}
this->SetBasisImages(images);
this->SetMeanImage(model->GetOutput(0));
}
template<class TInputImage, class TBasisImage>
void
ImagePCADecompositionCalculator<TInputImage, TBasisImage>
::PrintSelf( std::ostream& os, Indent indent ) const
{
Superclass::PrintSelf(os,indent);
os << indent << "Projection: " << m_Projection << std::endl;
os << indent << "Image: " << m_Image.GetPointer() << std::endl;
os << indent << "Mean Image: " << m_MeanImage.GetPointer() << std::endl;
}
} // end namespace itk
#endif
|
