1 #include "itkOtsuMultipleThresholdsCalculator.h"//包含头文件
2
3 #include "itkImage.h"
4 #include "itkImageFileReader.h"
5 #include "itkImageFileWriter.h"
6 #include "itkScalarImageToHistogramGenerator.h"
7 #include "itkBinaryThresholdImageFilter.h"
8 #include "itkNumericTraits.h"
9
10 #include <iomanip>
11 #include <stdio.h>
12 //这个例子阐述了如何使用 itk::OtsuMultipleThresholdsCalculator
13 int main( int argc, char * argv[] )
14 {
15 /*if( argc < 5 )
16 {
17 std::cerr << "Usage: " << argv[0];
18 std::cerr << " inputImageFile outputImageFileBase ";
19 std::cerr << " outputImageFileExtension numberOfThresholdsToCalculate " << std::endl;
20 return EXIT_FAILURE;
21 }*/
22
23 //Convenience typedefs
24 typedef unsigned short InputPixelType;
25 typedef unsigned char OutputPixelType;
26
27 typedef itk::Image< InputPixelType, 2 > InputImageType;
28 typedef itk::Image< OutputPixelType, 2 > OutputImageType;
29
30 /*OtsuMultipleThresholdsCalculator 以最大化类之间的变异的原则来计算一个给定的直方
31 图的门限。我们使用 ScalarImageToHistogramGenerator 来得到直方图*/
32 typedef itk::Statistics::ScalarImageToHistogramGenerator<
33 InputImageType > ScalarImageToHistogramGeneratorType;
34
35 typedef ScalarImageToHistogramGeneratorType::HistogramType HistogramType;
36
37 typedef itk::OtsuMultipleThresholdsCalculator< HistogramType > CalculatorType;
38
39 typedef itk::ImageFileReader< InputImageType > ReaderType;
40 typedef itk::ImageFileWriter< OutputImageType > WriterType;
41 //一旦计算得到门限值，我们将使用 BinaryThresholdImageFilter 来对图像进行分割
42 typedef itk::BinaryThresholdImageFilter<
43 InputImageType, OutputImageType > FilterType;
44
45 ScalarImageToHistogramGeneratorType::Pointer scalarImageToHistogramGenerator
46 = ScalarImageToHistogramGeneratorType::New();
47
48 CalculatorType::Pointer calculator = CalculatorType::New();
49 FilterType::Pointer filter = FilterType::New();
50
51 ReaderType::Pointer reader = ReaderType::New();
52 WriterType::Pointer writer = WriterType::New();
53
54 scalarImageToHistogramGenerator->SetNumberOfBins( 128 );
55 //设置Otsu分割阈值数目
56 calculator->SetNumberOfThresholds( atoi("3") );
57
58 const OutputPixelType outsideValue = 0;
59 const OutputPixelType insideValue = 255;
60
61 filter->SetOutsideValue( outsideValue );
62 filter->SetInsideValue( insideValue );
63
64 //Connect Pipeline
65 reader->SetFileName( "BrainProtonDensitySlice.png" );
66
67 //管道如下所示
68 scalarImageToHistogramGenerator->SetInput( reader->GetOutput() );
69 calculator->SetInputHistogram(scalarImageToHistogramGenerator->GetOutput() );
70 filter->SetInput( reader->GetOutput() );
71 writer->SetInput( filter->GetOutput() );
72 //读取报错异常
73 try
74 {
75 reader->Update();
76 }
77 catch( itk::ExceptionObject & excp )
78 {
79 std::cerr << "Exception thrown while reading image" << excp << std::endl;
80 }
81 scalarImageToHistogramGenerator->Compute();
82 //calculator报错异常
83 try
84 {
85 calculator->Compute();
86 }
87 catch( itk::ExceptionObject & excp )
88 {
89 std::cerr << "Exception thrown " << excp << std::endl;
90 }
91
92 //使用 GetOutput 方式可以得到门限值
93 const CalculatorType::OutputType &thresholdVector = calculator->GetOutput();
94
95 std::string outputFileBase = "BrainProtonDensitySlice_OtsuMu";
96
97 InputPixelType lowerThreshold = itk::NumericTraits<InputPixelType>::min();
98 InputPixelType upperThreshold;
99
100 typedef CalculatorType::OutputType::const_iterator ThresholdItType;
101
102 for( ThresholdItType itNum = thresholdVector.begin();
103 itNum != thresholdVector.end();
104 ++itNum )
105 {
106 std::cout << "OtsuThreshold["
107 << (int)(itNum - thresholdVector.begin())
108 << "] = "
109 << static_cast<itk::NumericTraits<
110 CalculatorType::MeasurementType>::PrintType>(*itNum)
111 << std::endl;
112
113 upperThreshold = static_cast<InputPixelType>(*itNum);
114
115 filter->SetLowerThreshold( lowerThreshold );
116 filter->SetUpperThreshold( upperThreshold );
117
118 lowerThreshold = upperThreshold;
119
120 std::ostringstream outputFilename;
121 outputFilename << outputFileBase
122 << std::setfill('0') << std::setw(3) << (itNum - thresholdVector.begin())
123 << "."
124 << "png";
125 writer->SetFileName( outputFilename.str() );
126
127 try
128 {
129 writer->Update();
130 }
131 catch( itk::ExceptionObject & excp )
132 {
133 std::cerr << "Exception thrown " << excp << std::endl;
134 }
135 }
136
137 upperThreshold = itk::NumericTraits<InputPixelType>::max();
138 filter->SetLowerThreshold( lowerThreshold );
139 filter->SetUpperThreshold( upperThreshold );
140
141 std::ostringstream outputFilename2;
142 outputFilename2 << outputFileBase
143 << std::setfill('0') << std::setw(3) << thresholdVector.size()
144 << "."
145 << "jpg";
146 writer->SetFileName( outputFilename2.str() );
147
148 try
149 {
150 writer->Update();
151 }
152 catch( itk::ExceptionObject & excp )
153 {
154 std::cerr << "Exception thrown " << excp << std::endl;
155 }
156
157 return EXIT_SUCCESS;
158 }
