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
|
/*=========================================================================
*
* 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 "itkMath.h"
#include "itkSigmoidImageFilter.h"
#include "itkTestingMacros.h"
int itkSigmoidImageFilterTest( int, char* [] )
{
// Define the dimension of the images
const unsigned int ImageDimension = 3;
// Declare the types of the images
typedef float InputPixelType;
typedef float OutputPixelType;
typedef itk::Image< InputPixelType, ImageDimension > InputImageType;
typedef itk::Image< OutputPixelType, ImageDimension > OutputImageType;
// Declare appropriate Iterator types for each image
typedef itk::ImageRegionIteratorWithIndex<
InputImageType> InputIteratorType;
typedef itk::ImageRegionIteratorWithIndex<
OutputImageType> OutputIteratorType;
// Declare the type of the index to access images
typedef itk::Index< ImageDimension > IndexType;
// Declare the type of the size
typedef itk::Size< ImageDimension > SizeType;
// Declare the type of the Region
typedef itk::ImageRegion< ImageDimension > RegionType;
// Create the input images
InputImageType::Pointer inputImage = InputImageType::New();
// Define their size, and start index
SizeType size;
size[0] = 2;
size[1] = 2;
size[2] = 2;
IndexType start;
start[0] = 0;
start[1] = 0;
start[2] = 0;
RegionType region;
region.SetIndex( start );
region.SetSize( size );
// Initialize the input image
inputImage->SetLargestPossibleRegion( region );
inputImage->SetBufferedRegion( region );
inputImage->SetRequestedRegion( region );
inputImage->Allocate();
// Create one iterator for the input image (this is a light object)
InputIteratorType it( inputImage, inputImage->GetBufferedRegion() );
// Initialize the content of the input image
const double value = 30;
it.GoToBegin();
while( !it.IsAtEnd() )
{
it.Set( value );
++it;
}
// Declare the type for the Sigmoid filter
typedef itk::SigmoidImageFilter< InputImageType,
OutputImageType > FilterType;
// Create the filter
FilterType::Pointer filter = FilterType::New();
EXERCISE_BASIC_OBJECT_METHODS( filter, SigmoidImageFilter,
UnaryFunctorImageFilter );
// Set the input image
filter->SetInput( inputImage );
// Set the filter parameters
const double alpha = 2.0;
const double beta = 3.0;
filter->SetAlpha( alpha );
TEST_SET_GET_VALUE( alpha, filter->GetAlpha() );
filter->SetBeta( beta );
TEST_SET_GET_VALUE( beta, filter->GetBeta() );
const OutputPixelType maximum = 1.0;
const OutputPixelType minimum = -1.0;
filter->SetOutputMinimum( minimum );
TEST_SET_GET_VALUE( minimum, filter->GetOutputMinimum() );
filter->SetOutputMaximum( maximum );
TEST_SET_GET_VALUE( maximum, filter->GetOutputMaximum() );
filter->SetFunctor( filter->GetFunctor() );
// Execute the filter
filter->Update();
// Get the filter output
OutputImageType::Pointer outputImage = filter->GetOutput();
// Create an iterator for going through the image output
OutputIteratorType ot( outputImage, outputImage->GetRequestedRegion() );
// Check the content of the result image
const OutputImageType::PixelType epsilon = 1e-6;
ot.GoToBegin();
it.GoToBegin();
while( !ot.IsAtEnd() )
{
const InputImageType::PixelType input = it.Get();
const OutputImageType::PixelType output = ot.Get();
const double x1 = ( input - beta ) / alpha;
const double x2 = ( maximum - minimum )*( 1.0 / ( 1.0 + std::exp( -x1 ) ) ) + minimum;
const OutputImageType::PixelType sigmoid =
static_cast<OutputImageType::PixelType>( x2 );
if( !itk::Math::FloatAlmostEqual( sigmoid, output, 10, epsilon ) )
{
std::cerr.precision( static_cast< int >( itk::Math::abs( std::log10( epsilon ) ) ) );
std::cerr << "Error " << std::endl;
std::cerr << " simoid( " << input << ") = " << sigmoid << std::endl;
std::cerr << " differs from " << output;
std::cerr << " by more than " << epsilon << std::endl;
return EXIT_FAILURE;
}
++ot;
++it;
}
return EXIT_SUCCESS;
}
|
