Compute Gradient Anisotropic Diffusion

Synopsis

Perform anisotropic diffusion on an image.

Results

Input image

Input image

Output image

Output image

Code

C++

#include "itkImageFileReader.h"
#include "itkImageFileWriter.h"
#include "itkGradientAnisotropicDiffusionImageFilter.h"
#include "itkRescaleIntensityImageFilter.h"

int
main(int argc, char * argv[])
{
  if (argc != 6)
  {
    std::cerr << "Usage: " << std::endl;
    std::cerr << argv[0];
    std::cerr << " <InputFileName> <OutputFileName>";
    std::cerr << " <numberOfIterations> <timeStep> <conductance>";
    std::cerr << std::endl;
    return EXIT_FAILURE;
  }

  const char * inputFileName = argv[1];
  const char * outputFileName = argv[2];

  constexpr unsigned int Dimension = 2;

  using InputPixelType = float;
  using InputImageType = itk::Image<InputPixelType, Dimension>;
  using OutputPixelType = unsigned char;
  using OutputImageType = itk::Image<OutputPixelType, Dimension>;

  const int            numberOfIterations = std::stoi(argv[3]);
  const InputPixelType timeStep = std::stod(argv[4]);
  const InputPixelType conductance = std::stod(argv[5]);

  using ReaderType = itk::ImageFileReader<InputImageType>;
  ReaderType::Pointer reader = ReaderType::New();
  reader->SetFileName(inputFileName);

  using FilterType = itk::GradientAnisotropicDiffusionImageFilter<InputImageType, InputImageType>;
  FilterType::Pointer filter = FilterType::New();
  filter->SetInput(reader->GetOutput());
  filter->SetNumberOfIterations(numberOfIterations);
  filter->SetTimeStep(timeStep);
  filter->SetConductanceParameter(conductance);

  using RescaleType = itk::RescaleIntensityImageFilter<InputImageType, OutputImageType>;
  RescaleType::Pointer rescaler = RescaleType::New();
  rescaler->SetInput(filter->GetOutput());
  rescaler->SetOutputMinimum(itk::NumericTraits<OutputPixelType>::min());
  rescaler->SetOutputMaximum(itk::NumericTraits<OutputPixelType>::max());

  using WriterType = itk::ImageFileWriter<OutputImageType>;
  WriterType::Pointer writer = WriterType::New();
  writer->SetFileName(outputFileName);
  writer->SetInput(rescaler->GetOutput());

  try
  {
    writer->Update();
  }
  catch (itk::ExceptionObject & error)
  {
    std::cerr << "Error: " << error << std::endl;
    return EXIT_FAILURE;
  }

  return EXIT_SUCCESS;
}

Python

#!/usr/bin/env python
import itk

if len(sys.argv) != 6:
    print("Usage: " + sys.argv[0] + " <inputImage> <outputImage> "
          "<numberOfIterations> <timeStep> <conductance>")
    sys.exit(1)

inputImage = sys.argv[1]
outputImage = sys.argv[2]
numberOfIterations = int(sys.argv[3])
timeStep = float(sys.argv[4])
conductance = float(sys.argv[5])

InputPixelType = itk.F
OutputPixelType = itk.UC
Dimension = 2

InputImageType = itk.Image[InputPixelType, Dimension]
OutputImageType = itk.Image[OutputPixelType, Dimension]

ReaderType = itk.ImageFileReader[InputImageType]
reader = ReaderType.New()
reader.SetFileName(inputImage)

FilterType = itk.GradientAnisotropicDiffusionImageFilter[
    InputImageType, InputImageType]
gradientAnisotropicDiffusionFilter = FilterType.New()

gradientAnisotropicDiffusionFilter.SetInput(reader.GetOutput())
gradientAnisotropicDiffusionFilter.SetNumberOfIterations(numberOfIterations)
gradientAnisotropicDiffusionFilter.SetTimeStep(timeStep)
gradientAnisotropicDiffusionFilter.SetConductanceParameter(conductance)

RescaleFilterType = itk.RescaleIntensityImageFilter[
    InputImageType, OutputImageType]
rescaler = RescaleFilterType.New()
rescaler.SetInput(gradientAnisotropicDiffusionFilter.GetOutput())

outputPixelTypeMinimum = itk.NumericTraits[OutputPixelType].min()
outputPixelTypeMaximum = itk.NumericTraits[OutputPixelType].max()

rescaler.SetOutputMinimum(outputPixelTypeMinimum)
rescaler.SetOutputMaximum(outputPixelTypeMaximum)

WriterType = itk.ImageFileWriter[OutputImageType]
writer = WriterType.New()
writer.SetFileName(outputImage)
writer.SetInput(rescaler.GetOutput())

writer.Update()

Classes demonstrated