1、代码

 1 #include "itkConnectedComponentImageFilter.h"
 2 #include "itkImage.h"
 3 #include "itkImageFileReader.h"
 4 #include "itkImageFileWriter.h"
 5 #include "itkImageRegionIterator.h"
 6 #include "itkLabelShapeKeepNObjectsImageFilter.h"
 7 
 8 using namespace std;
 9 
10 void print(const std::string& file, itk::Image<unsigned char, 2>* image)
11 {
12     ofstream fout(file);
13     auto size = image->GetBufferedRegion().GetSize();
14     for (auto i = 0; i < size[0]; i++)
15     {
16         for (auto j = 0; j < size[1]; j++)
17         {
18             itk::Image<unsigned char, 2>::IndexType index{ {i,j} };
19             auto c = image->GetPixel(index);
20             fout << (int)c;
21         }
22         fout << std::endl;
23     }
24 }
25 
26 
27 int main(int argc, char *argv[])
28 {
29     // 1、获取二值化的分割结果mask
30     const char* input_path = "D:/documents/vs2019/itk_tutorial/largestcompent/build/RelWithDebInfo/left_femur.nrrd";// 图像保存的路径
31     using ImageType = itk::Image<unsigned char, 3>;
32     using ReaderFilter = itk::ImageFileReader<ImageType>;
33     auto reader = ReaderFilter::New();
34     reader->SetFileName(input_path);
35     reader->Update();
36     ImageType::Pointer image = reader->GetOutput();
37 
38     // 2, 调用ITK的itkConnectedComponentImageFilter
39     using ConnectedComponentFilter = itk::ConnectedComponentImageFilter<ImageType, ImageType>;
40     auto connnectedComponentFilter = ConnectedComponentFilter::New();
41     connnectedComponentFilter->SetInput(image);
42     connnectedComponentFilter->Update();
43 
44     // 3,调用ITK的itkLabelShapeKeepNObjectsImageFilter
45     using LabelShapeKeepNObjectsFilter = itk::LabelShapeKeepNObjectsImageFilter<ImageType>;
46     auto labelShapeKeepNObjectsFilter = LabelShapeKeepNObjectsFilter::New();
47     labelShapeKeepNObjectsFilter->SetInput(connnectedComponentFilter->GetOutput());
48     labelShapeKeepNObjectsFilter->SetBackgroundValue(0);
49     labelShapeKeepNObjectsFilter->SetNumberOfObjects(1);
50     labelShapeKeepNObjectsFilter->SetAttribute(
51         LabelShapeKeepNObjectsFilter::LabelObjectType::NUMBER_OF_PIXELS);
52     labelShapeKeepNObjectsFilter->Update();
53 // 4、将Label便签转换为1
54  typedef itk::RescaleIntensityImageFilter<ImageType, ImageType> RescaleFilterType;
55   RescaleFilterType::Pointer rescaleFilter = RescaleFilterType::New();
56   rescaleFilter->SetOutputMinimum(0);
57   rescaleFilter->SetOutputMaximum(1);
58   rescaleFilter->SetInput(labelShapeKeepNObjectsFilter->GetOutput());
59   rescaleFilter->Update();
60   //ImageType::Pointer largestccimage = rescaleFilter->GetOutput(); 
61 
62     // 5,保存最大连通区域图像
63 
64     const char* out_path = "D:/documents/vs2019/itk_tutorial/largestcompent/build/RelWithDebInfo/output.nii.gz"; // 保存输出结果的路径
65     using WriterFilter = itk::ImageFileWriter<ImageType>;
66     auto writer = WriterFilter::New();
67     writer->SetFileName(out_path);
68     writer->SetInput(rescaleFilter->GetOutput());
69     writer->Update();
70      
71     return EXIT_SUCCESS;
72 }

2、效果

原始图像：

去除小连通域之后

3、主要函数介绍

itk::ConnectedComponentImageFilter<ImageType, OutputImageType>;

该filter值检测连通区域，不编号，不排序。

itk::LabelShapeKeepNObjectsImageFilter;

该filter对连通区域进行排序，然后只保留最大的几个连通区域。

itk::LabelImageToShapeLabelMapFilter< OutputImageType, LabelMapType> ;

为保留的每个连通区域打上标签（标号），编号顺序为找到不同区域的顺序.

虽然LabelShapeKeepNObjectsImageFilter调用SetAttribute 之后，按照attribute对连通区域大小进行了排序，但该排序并不反映在label上。即大的label并不一定对应大的size。反映在 SetNumberOfObjects(n) 设定保留区域之后，只保留排序后前n个区域的label。

itk::RescaleIntensityImageFilter<OutputImageType, ImageType>；

上一步图像只有标签，图像上没有直接的区别，本步对保留下来的不同连通区域进行不同的染色，以示区分。

posted on 2023-07-13 14:31 一杯清酒邀明月阅读(439) 评论(0) 编辑收藏举报