ITK/Examples/Segmentation/VoronoiDiagram2DGenerator

VoronoiDiagram2DGenerator.cxx

<source lang="cpp">

1. include "itkVoronoiDiagram2DGenerator.h"
2. include "itkImageFileWriter.h"
3. include "itkVTKPolyDataWriter.h"

int main( int, char* [] ) {

 constexpr double height = 100;
 constexpr double width = 100;

 using VoronoiDiagramType = itk::VoronoiDiagram2D<double>;
 using VoronoiGeneratorType = itk::VoronoiDiagram2DGenerator<double>;

 using PointType = VoronoiDiagramType::PointType;
 using CellType = VoronoiDiagramType::CellType;
 using CellAutoPointer = VoronoiDiagramType::CellAutoPointer;
 using PointIdIterator = CellType::PointIdIterator;
 using NeighborIdIterator = VoronoiDiagramType::NeighborIdIterator;

 VoronoiDiagramType::Pointer voronoiDiagram = VoronoiDiagramType::New();
 VoronoiGeneratorType::Pointer voronoiGenerator = VoronoiGeneratorType::New();

 PointType insize;
 insize[0] = width;
 insize[1] = height;
 voronoiGenerator->SetBoundary(insize);

 // Create a list of seeds
 std::vector<PointType> seeds;
 PointType seed0;
 seed0[0] = 50;
 seed0[1] = 50;
 seeds.push_back(seed0);

 PointType seed1;
 seed1[0] = 25;
 seed1[1] = 25;
 seeds.push_back(seed1);

 PointType seed2;
 seed2[0] = 75;
 seed2[1] = 25;
 seeds.push_back(seed2);

 PointType seed3;
 seed3[0] = 25;
 seed3[1] = 75;
 seeds.push_back(seed3);

 PointType seed4;
 seed4[0] = 75;
 seed4[1] = 75;
 seeds.push_back(seed4);

 for(const auto & seed : seeds)
   {
   voronoiGenerator->AddOneSeed(seed);
   }

 voronoiGenerator->Update();
 voronoiDiagram = voronoiGenerator->GetOutput();

 for(unsigned int i = 0; i < seeds.size(); i++)
   {
   PointType currP = voronoiDiagram->GetSeed(i);
   std::cout << "Seed No." << i << ": At (" << currP[0] << "," << currP[1] << ")" << std::endl;
   std::cout << "  Boundary Vertices List (in order):";
   CellAutoPointer currCell;
   voronoiDiagram->GetCellId(i, currCell);
   PointIdIterator currCellP;
   for(currCellP = currCell->PointIdsBegin(); currCellP != currCell->PointIdsEnd(); ++currCellP)
     {
     std::cout << (*currCellP) << ",";
     }
   std::cout << std::endl;
   std::cout << "  Neighbors (Seed No.):";
   NeighborIdIterator currNeibor;
   for(currNeibor = voronoiDiagram->NeighborIdsBegin(i); currNeibor != voronoiDiagram->NeighborIdsEnd(i); ++currNeibor)
     {
     std::cout << (*currNeibor) << ",";
     }
   std::cout << std::endl << std::endl;
   }

 std::cout << "Vertices Informations:" << std::endl;
 VoronoiDiagramType::VertexIterator allVerts;
 int j = 0;
 for(allVerts = voronoiDiagram->VertexBegin(); allVerts != voronoiDiagram->VertexEnd(); ++allVerts)
   {
   std::cout << "Vertices No." << j;
   j++;

1. if ITK_VERSION_MAJOR < 4

   std::cout << ": At (" << (*allVerts)[0] << "," << (*allVerts)[1] << ")" << std::endl;

1. else

   std::cout << ": At (" << (allVerts.Value())[0] << "," << (allVerts.Value())[1] << ")" << std::endl;

1. endif

   }

 // Write the resulting mesh
 using WriterType = itk::VTKPolyDataWriter<VoronoiDiagramType::Superclass>;
 WriterType::Pointer vtkPolyDataWriter = WriterType::New();
 vtkPolyDataWriter->SetInput(voronoiDiagram);
 vtkPolyDataWriter->SetFileName("voronoi.vtk");
 vtkPolyDataWriter->Update();

 // Setup an image to visualize the input
 {
 using ImageType = itk::Image< unsigned char, 2>;

 ImageType::IndexType start;
 start.Fill(0);

 ImageType::SizeType size;
 size.Fill(100);

 ImageType::RegionType region(start,size);

 ImageType::Pointer image = ImageType::New();
 image->SetRegions(region);
 image->Allocate();
 image->FillBuffer(0);

 ImageType::IndexType ind;
 ind[0] = 50;
 ind[1] = 50;
 image->SetPixel(ind, 255);

 ind[0] = 25;
 ind[1] = 25;
 image->SetPixel(ind, 255);

 ind[0] = 75;
 ind[1] = 25;
 image->SetPixel(ind, 255);

 ind[0] = 25;
 ind[1] = 75;
 image->SetPixel(ind, 255);

 ind[0] = 75;
 ind[1] = 75;
 image->SetPixel(ind, 255);

 using ImageWriterType = itk::ImageFileWriter< ImageType  >;
 ImageWriterType::Pointer imageFileWriter = ImageWriterType::New();
 imageFileWriter->SetFileName("image.png");
 imageFileWriter->SetInput(image);
 imageFileWriter->Update();
 }

 return EXIT_SUCCESS;

}

</source>

CMakeLists.txt

<syntaxhighlight lang="cmake"> cmake_minimum_required(VERSION 3.9.5)

project(VoronoiDiagram2DGenerator)

find_package(ITK REQUIRED) include(${ITK_USE_FILE}) if (ITKVtkGlue_LOADED)

 find_package(VTK REQUIRED)
 include(${VTK_USE_FILE})

endif()

add_executable(VoronoiDiagram2DGenerator MACOSX_BUNDLE VoronoiDiagram2DGenerator.cxx)

if( "${ITK_VERSION_MAJOR}" LESS 4 )

 target_link_libraries(VoronoiDiagram2DGenerator ITKReview ${ITK_LIBRARIES})

else( "${ITK_VERSION_MAJOR}" LESS 4 )

 target_link_libraries(VoronoiDiagram2DGenerator ${ITK_LIBRARIES})

endif( "${ITK_VERSION_MAJOR}" LESS 4 )

</syntaxhighlight>

Download and Build VoronoiDiagram2DGenerator

Click here to download VoronoiDiagram2DGenerator and its CMakeLists.txt file. Once the tarball VoronoiDiagram2DGenerator.tar has been downloaded and extracted,

cd VoronoiDiagram2DGenerator/build

• If ITK is installed:

cmake ..

• If ITK is not installed but compiled on your system, you will need to specify the path to your ITK build:

cmake -DITK_DIR:PATH=/home/me/itk_build ..

Build the project:

make

and run it:

./VoronoiDiagram2DGenerator

WINDOWS USERS PLEASE NOTE: Be sure to add the ITK bin directory to your path. This will resolve the ITK dll's at run time.

Building All of the Examples

Many of the examples in the ITK Wiki Examples Collection require VTK. You can build all of the the examples by following these instructions. If you are a new VTK user, you may want to try the Superbuild which will build a proper ITK and VTK.

ItkVtkGlue

ITK >= 4

For examples that use QuickView (which depends on VTK), you must have built ITK with Module_ITKVtkGlue=ON.

ITK < 4

Some of the ITK Examples require VTK to display the images. If you download the entire ITK Wiki Examples Collection, the ItkVtkGlue directory will be included and configured. If you wish to just build a few examples, then you will need to download ItkVtkGlue and build it. When you run cmake it will ask you to specify the location of the ItkVtkGlue binary directory.