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
|
/*=========================================================================
*
* Copyright Insight Software Consortium
*
* 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
*
* http://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.
*
*=========================================================================*/
#include "itkInverseDisplacementFieldImageFilter.h"
#include "itkImageFileWriter.h"
#include "itkFilterWatcher.h"
int itkInverseDisplacementFieldImageFilterTest( int argc, char * argv[] )
{
if( argc < 2 )
{
std::cerr << "Missing Parameters " << std::endl;
std::cerr << "Usage: " << argv[0];
std::cerr << " outputImage" << std::endl;
return EXIT_FAILURE;
}
const unsigned int Dimension = 2;
typedef float VectorComponentType;
typedef itk::Vector< VectorComponentType, Dimension > VectorType;
typedef itk::Image< VectorType, Dimension > DisplacementFieldType;
typedef itk::InverseDisplacementFieldImageFilter<
DisplacementFieldType,
DisplacementFieldType
> FilterType;
FilterType::Pointer filter = FilterType::New();
FilterWatcher watcher(filter);
// Creating an input displacement field
DisplacementFieldType::Pointer field = DisplacementFieldType::New();
DisplacementFieldType::SpacingType spacing;
spacing.Fill( 1.0 );
DisplacementFieldType::PointType origin;
origin.Fill( 0.0 );
DisplacementFieldType::RegionType region;
DisplacementFieldType::SizeType size;
DisplacementFieldType::IndexType start;
size[0] = 128;
size[1] = 128;
start[0] = 0;
start[1] = 0;
region.SetSize( size );
region.SetIndex( start );
field->SetOrigin( origin );
field->SetSpacing( spacing );
field->SetRegions( region );
field->Allocate();
VectorType pixelValue;
itk::ImageRegionIteratorWithIndex< DisplacementFieldType > it( field, region );
// Fill the field with some vectors
it.GoToBegin();
while( !it.IsAtEnd() )
{
DisplacementFieldType::IndexType index = it.GetIndex();
pixelValue[0] = index[0] * 2.0 - index[0];
pixelValue[1] = index[1] * 2.0 - index[1];
it.Set( pixelValue );
++it;
}
// Since the tested transform is upsampling by a factor of two, the
// size of the inverse field should be twice the size of the input
// field. All other geomtry parameters are the same.
filter->SetOutputSpacing( spacing );
// keep the origin
filter->SetOutputOrigin( origin );
// set the size
DisplacementFieldType::SizeType invFieldSize;
invFieldSize[0] = size[0] * 2;
invFieldSize[1] = size[1] * 2;
filter->SetSize( invFieldSize );
filter->SetInput( field );
filter->SetSubsamplingFactor( 16 );
try
{
filter->UpdateLargestPossibleRegion();
}
catch( itk::ExceptionObject & excp )
{
std::cerr << "Exception thrown " << std::endl;
std::cerr << excp << std::endl;
}
// Write an image for regression testing
typedef itk::ImageFileWriter< DisplacementFieldType > WriterType;
WriterType::Pointer writer = WriterType::New();
writer->SetInput (filter->GetOutput() );
writer->SetFileName( argv[1] );
try
{
writer->Update();
}
catch( itk::ExceptionObject & excp )
{
std::cerr << "Exception thrown by writer" << std::endl;
std::cerr << excp << std::endl;
return EXIT_FAILURE;
}
// Now, test for loop invariant (acts as filter validation)
// f^-1(f(p1) + p1 ) - f(p1) = 0
it.GoToBegin();
while( !it.IsAtEnd() )
{
DisplacementFieldType::PointType p1;
field->TransformIndexToPhysicalPoint(it.GetIndex(), p1);
DisplacementFieldType::PixelType fp1 = it.Get();
DisplacementFieldType::PointType p2;
p2[0] = p1[0] + fp1[0];
p2[1] = p1[1] + fp1[1];
DisplacementFieldType::IndexType id2;
filter->GetOutput()->TransformPhysicalPointToIndex(p2,id2);
DisplacementFieldType::PixelType fp2 = filter->GetOutput()->GetPixel(id2);
if(std::abs(fp2[0] + fp1[0]) > 0.001
|| std::abs(fp2[1] + fp1[1]) > 0.001)
{
std::cerr<<"Loop invariant not satisfied for index "<<it.GetIndex()<<" : f^-1(f(p1) + p1 ) + f(p1) = 0"<< std::endl;
std::cerr<<"f(p1) = "<<fp1<<std::endl;
std::cerr<<"f^-1(f(p1) + p1 ) = "<<fp2<<std::endl;
std::cerr<<"diff: "<<fp1[0]+fp2[0]<<", "<<fp1[1]+fp2[1]<<std::endl;
return EXIT_FAILURE;
}
++it;
}
return EXIT_SUCCESS;
}
|
