1 /*=========================================================================
2 *
3 * Copyright Insight Software Consortium
4 *
5 * Licensed under the Apache License, Version 2.0 (the "License");
6 * you may not use this file except in compliance with the License.
7 * You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0.txt
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 *
17 *=========================================================================*/
18
19 #include "itkAtanImageFilter.h"
20 #include "itkAtanImageAdaptor.h"
21 #include "itkMath.h"
22 #include "itkSubtractImageFilter.h"
23 #include "itkTestingMacros.h"
24
25
itkAtanImageFilterAndAdaptorTest(int,char * [])26 int itkAtanImageFilterAndAdaptorTest( int, char* [] )
27 {
28
29 // Define the dimension of the images
30 constexpr unsigned int ImageDimension = 3;
31
32 // Declare the pixel types of the images
33 using PixelType = float;
34
35 // Declare the types of the images
36 using InputImageType = itk::Image< PixelType, ImageDimension >;
37 using OutputImageType = itk::Image< PixelType, ImageDimension >;
38
39 // Declare appropriate Iterator types for each image
40 using InputIteratorType = itk::ImageRegionIteratorWithIndex<InputImageType>;
41 using OutputIteratorType = itk::ImageRegionIteratorWithIndex<OutputImageType>;
42
43 // Declare the type of the index to access images
44 using IndexType = itk::Index< ImageDimension >;
45
46 // Declare the type of the size
47 using SizeType = itk::Size< ImageDimension >;
48
49 // Declare the type of the Region
50 using RegionType = itk::ImageRegion< ImageDimension >;
51
52 // Create the input image
53 InputImageType::Pointer inputImage = InputImageType::New();
54
55 // Define their size, and start index
56 SizeType size;
57 size[0] = 2;
58 size[1] = 2;
59 size[2] = 2;
60
61 IndexType start;
62 start[0] = 0;
63 start[1] = 0;
64 start[2] = 0;
65
66 RegionType region;
67 region.SetIndex( start );
68 region.SetSize( size );
69
70 // Initialize Image A
71 inputImage->SetLargestPossibleRegion( region );
72 inputImage->SetBufferedRegion( region );
73 inputImage->SetRequestedRegion( region );
74 inputImage->Allocate();
75
76 // Create one iterator for the Input Image (this is a light object)
77 InputIteratorType it( inputImage, inputImage->GetBufferedRegion() );
78
79 // Initialize the content of Image A
80 const double value = itk::Math::pi / 6.0;
81 it.GoToBegin();
82 while( !it.IsAtEnd() )
83 {
84 it.Set( value );
85 ++it;
86 }
87
88 // Declare the type for the Atan filter
89 using FilterType = itk::AtanImageFilter< InputImageType, OutputImageType >;
90
91 // Create the Filter
92 FilterType::Pointer filter = FilterType::New();
93
94 EXERCISE_BASIC_OBJECT_METHODS( filter, AtanImageFilter,
95 UnaryGeneratorImageFilter );
96
97 // Set the input image
98 filter->SetInput( inputImage );
99
100
101 // Execute the filter
102 filter->Update();
103
104 // Get the filter output
105 OutputImageType::Pointer outputImage = filter->GetOutput();
106
107 // Create an iterator for going through the image output
108 OutputIteratorType ot( outputImage, outputImage->GetRequestedRegion() );
109
110 // Check the content of the result image
111 const OutputImageType::PixelType epsilon = 1e-6;
112 ot.GoToBegin();
113 it.GoToBegin();
114 while( !ot.IsAtEnd() )
115 {
116 const InputImageType::PixelType input = it.Get();
117 const OutputImageType::PixelType output = ot.Get();
118 const OutputImageType::PixelType arctangent = std::atan(input);
119 if( !itk::Math::FloatAlmostEqual( arctangent, output, 10, epsilon ) )
120 {
121 std::cerr.precision( static_cast< int >( itk::Math::abs( std::log10( epsilon ) ) ) );
122 std::cerr << "Error " << std::endl;
123 std::cerr << " std::atan( " << input << ") = " << arctangent << std::endl;
124 std::cerr << " differs from " << output;
125 std::cerr << " by more than " << epsilon << std::endl;
126 return EXIT_FAILURE;
127 }
128 ++ot;
129 ++it;
130 }
131
132
133 //
134 // Test the itk::AtanImageAdaptor
135 //
136
137 using AdaptorType = itk::AtanImageAdaptor< InputImageType,
138 OutputImageType::PixelType >;
139
140 AdaptorType::Pointer atanAdaptor = AdaptorType::New();
141
142 EXERCISE_BASIC_OBJECT_METHODS( atanAdaptor, AtanImageAdaptor,
143 ImageAdaptor );
144
145 atanAdaptor->SetImage( inputImage );
146
147 using DiffFilterType = itk::SubtractImageFilter<
148 OutputImageType,
149 AdaptorType,
150 OutputImageType >;
151
152 DiffFilterType::Pointer diffFilter = DiffFilterType::New();
153
154 diffFilter->SetInput1( outputImage );
155 diffFilter->SetInput2( atanAdaptor );
156
157 diffFilter->Update();
158
159 // Get the filter output
160 OutputImageType::Pointer diffImage = diffFilter->GetOutput();
161
162 // Check the content of the diff image
163 //
164
165 // Create an iterator for going through the image output
166 OutputIteratorType dt( diffImage, diffImage->GetRequestedRegion() );
167
168 dt.GoToBegin();
169 while( !dt.IsAtEnd() )
170 {
171 const OutputImageType::PixelType diff = dt.Get();
172 if( std::fabs( diff ) > epsilon )
173 {
174 std::cerr.precision( static_cast< int >( itk::Math::abs( std::log10( epsilon ) ) ) );
175 std::cerr << "Error comparing results with Adaptors" << std::endl;
176 std::cerr << " difference = " << diff << std::endl;
177 std::cerr << " differs from 0 ";
178 std::cerr << " by more than " << epsilon << std::endl;
179 return EXIT_FAILURE;
180 }
181 ++dt;
182 }
183
184 return EXIT_SUCCESS;
185
186 }
187