ITK/Examples/Smoothing/VectorGradientAnisotropicDiffusionImageFilter

This example illustrates how to process an RGB image with a filter that accepts Vector images.

VectorGradientAnisotropicDiffusionImageFilter.cxx

<source lang="cpp">

1. include "itkImage.h"
2. include "itkCastImageFilter.h"
3. include "itkImageFileReader.h"
4. include "itkVectorGradientAnisotropicDiffusionImageFilter.h"
5. include "itkVectorToRGBImageAdaptor.h"
6. include "itkRGBToVectorImageAdaptor.h"
7. include "itkCastImageFilter.h"

1. include "itksys/SystemTools.hxx"
2. include <sstream>

1. include "QuickView.h"

int main( int argc, char *argv[]) {

 // Verify arguments
 if( argc < 2 )
   {
   std::cerr << "Usage: "<< std::endl;
   std::cerr << argv[0];
   std::cerr << " InputFileName";
   std::cerr << " [NumberOfIterations] ";
   std::cerr << " [Conductance]" << std::endl;
   return EXIT_FAILURE;
   }
 
 // 0) Parse arguments
 std::string inputFileName = argv[1];

 typedef itk::Image< itk::Vector<float, 3>, 2 >  FloatImageType;
 typedef itk::Image< itk::RGBPixel<float>, 2 >   RGBImageType;
 
 // 1) Read the RGB image
 typedef  itk::ImageFileReader< RGBImageType > ReaderType;
 ReaderType::Pointer reader = ReaderType::New();
 reader->SetFileName( inputFileName );

 // 2) Cast to Vector image for processing
 typedef itk::RGBToVectorImageAdaptor<RGBImageType> AdaptorInputType;
 AdaptorInputType::Pointer adaptInput = AdaptorInputType::New();
 adaptInput->SetImage(reader->GetOutput());
 typedef itk::CastImageFilter<AdaptorInputType,FloatImageType> CastInputType;
 CastInputType::Pointer castInput = CastInputType::New();
 castInput->SetInput(adaptInput);

 // 3) Smooth the image
 typedef itk::VectorGradientAnisotropicDiffusionImageFilter< FloatImageType, 
   FloatImageType > VectorGradientAnisotropicDiffusionImageFilterType;
 VectorGradientAnisotropicDiffusionImageFilterType::Pointer filter = 
   VectorGradientAnisotropicDiffusionImageFilterType::New();
 filter->SetInput( castInput->GetOutput() );
 filter->SetTimeStep(0.125);
 if (argc > 2)
   {
   filter->SetNumberOfIterations(atoi(argv[2]));
   }
 if (argc > 3)
   {
   filter->SetConductanceParameter(atof(argv[3]));
   }

 // 4) Cast the Vector image to an RGB image for display
 typedef itk::VectorToRGBImageAdaptor<FloatImageType> AdaptorOutputType;
 AdaptorOutputType::Pointer adaptOutput = AdaptorOutputType::New();
 adaptOutput->SetImage(filter->GetOutput());
 typedef itk::CastImageFilter<AdaptorOutputType,RGBImageType> CastOutputType;
 CastOutputType::Pointer castOutput = CastOutputType::New();
 castOutput->SetInput(adaptOutput);
 
 // 5) Display the inut and smoothed images
 QuickView viewer;
 viewer.AddRGBImage(
   reader->GetOutput(),
   true,
   itksys::SystemTools::GetFilenameName(inputFileName));  

 std::stringstream desc;
 desc << "VectorGradientAnisotropicDiffusionImageFilter\niterations: "
      << filter->GetNumberOfIterations() << " conductance: "
      << filter->GetConductanceParameter();
 viewer.AddRGBImage(
   castOutput->GetOutput(),
   true,
   desc.str());  

 viewer.Visualize();

 return EXIT_SUCCESS;

} </source>

CMakeLists.txt

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

project(VectorGradientAnisotropicDiffusionImageFilter)

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

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

endif()

add_executable(VectorGradientAnisotropicDiffusionImageFilter MACOSX_BUNDLE VectorGradientAnisotropicDiffusionImageFilter.cxx)

if( "${ITK_VERSION_MAJOR}" LESS 4 )

 target_link_libraries(VectorGradientAnisotropicDiffusionImageFilter ITKReview ${ITK_LIBRARIES})

else( "${ITK_VERSION_MAJOR}" LESS 4 )

 target_link_libraries(VectorGradientAnisotropicDiffusionImageFilter ${ITK_LIBRARIES})

endif( "${ITK_VERSION_MAJOR}" LESS 4 )

</syntaxhighlight>

Download and Build VectorGradientAnisotropicDiffusionImageFilter

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

cd VectorGradientAnisotropicDiffusionImageFilter/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:

./VectorGradientAnisotropicDiffusionImageFilter

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.