ITK  5.2.0
Insight Toolkit
Examples/Filtering/SignedDanielssonDistanceMapImageFilter.cxx
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// Software Guide : BeginLatex
//
// This example illustrates the use of the
// \doxygen{SignedDanielssonDistanceMapImageFilter}. This filter generates a
// distance map by running Danielsson distance map twice, once on the input
// image and once on the flipped image.
//
// \index{itk::Signed\-Danielsson\-Distance\-Map\-Image\-Filter!Instantiation}
// \index{itk::Signed\-Danielsson\-Distance\-Map\-Image\-Filter!Header}
//
// The first step required to use this filter is to include its header file.
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
// Software Guide : EndCodeSnippet
#include "itkImage.h"
int
main(int argc, char * argv[])
{
if (argc < 5)
{
std::cerr << "Usage: " << argv[0];
std::cerr << " inputImageFile outputDistanceMapImageFile ";
std::cerr << " outputVoronoiMapImageFilter ";
std::cerr << " outputVectorMapImageFilter ";
std::cerr << std::endl;
return EXIT_FAILURE;
}
// Software Guide : BeginLatex
//
// Then we must decide what pixel types to use for the input and output
// images. Since the output will contain distances measured in pixels, the
// pixel type should be able to represent at least the width of the image,
// or said in $N$-dimensional terms, the maximum extension along all the
// dimensions. The input and output image types are now defined using their
// respective pixel type and dimension.
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
using InputPixelType = unsigned char;
using OutputPixelType = float;
using VoronoiPixelType = unsigned short;
constexpr unsigned int Dimension = 2;
using InputImageType = itk::Image<InputPixelType, Dimension>;
using OutputImageType = itk::Image<OutputPixelType, Dimension>;
using VoronoiImageType = itk::Image<VoronoiPixelType, Dimension>;
// Software Guide : EndCodeSnippet
// Software Guide : BeginLatex
//
// The only change with respect to the previous example is to replace the
// DanielssonDistanceMapImageFilter with the
// SignedDanielssonDistanceMapImageFilter.
//
// SoftwareGuide : EndLatex
// Software Guide : BeginCodeSnippet
using FilterType =
OutputImageType,
VoronoiImageType>;
FilterType::Pointer filter = FilterType::New();
// Software Guide : EndCodeSnippet
using RescalerType =
RescalerType::Pointer scaler = RescalerType::New();
// Software Guide : BeginLatex
//
// The distances inside the circle are defined to be negative, while the
// distances outside the circle are positive. To change the convention,
// use the \code{InsideIsPositive(bool)} function.
//
// Software Guide : EndLatex
// Reader and Writer types are instantiated.
//
using VoronoiWriterType = itk::ImageFileWriter<VoronoiImageType>;
ReaderType::Pointer reader = ReaderType::New();
WriterType::Pointer writer = WriterType::New();
reader->SetFileName(argv[1]);
writer->SetFileName(argv[2]);
// The input to the filter is taken from a reader and its output is passed
// to a \doxygen{RescaleIntensityImageFilter} and then to a writer.
filter->SetInput(reader->GetOutput());
scaler->SetInput(filter->GetOutput());
writer->SetInput(scaler->GetOutput());
scaler->SetOutputMaximum(65535L);
scaler->SetOutputMinimum(0L);
try
{
writer->Update();
}
catch (const itk::ExceptionObject & exp)
{
std::cerr << "Exception caught !" << std::endl;
std::cerr << exp << std::endl;
}
const char * voronoiMapFileName = argv[3];
// The Voronoi map is obtained with the \code{GetVoronoiMap()} method. In
// the lines below we connect this output to the intensity rescaler and
// save the result in a file.
//
// \index{itk::Danielsson\-Distance\-Map\-Image\-Filter!GetVoronoiMap()}
//
VoronoiWriterType::Pointer voronoiWriter = VoronoiWriterType::New();
voronoiWriter->SetFileName(voronoiMapFileName);
voronoiWriter->SetInput(filter->GetVoronoiMap());
try
{
voronoiWriter->Update();
}
catch (const itk::ExceptionObject & exp)
{
std::cerr << "Exception caught !" << std::endl;
std::cerr << exp << std::endl;
}
// The distance filter also produces an image of \doxygen{Offset} pixels
// representing the vectorial distance to the closest object in the scene.
// The type of this output image is defined by the VectorImageType
// trait of the filter type.
using OffsetImageType = FilterType::VectorImageType;
// We can use this type for instantiating an \doxygen{ImageFileWriter} type
// and creating an object of this class in the following lines.
using WriterOffsetType = itk::ImageFileWriter<OffsetImageType>;
WriterOffsetType::Pointer offsetWriter = WriterOffsetType::New();
offsetWriter->SetInput(filter->GetVectorDistanceMap());
offsetWriter->SetFileName(argv[4]);
try
{
offsetWriter->Update();
}
catch (const itk::ExceptionObject & exp)
{
std::cerr << "Exception caught !" << std::endl;
std::cerr << exp << std::endl;
}
// Software Guide : BeginLatex
//
// \begin{figure}
// \center
// \includegraphics[width=0.32\textwidth]{Circle}
// \includegraphics[width=0.32\textwidth]{SignedDanielssonDistanceMapImageFilterOutput}
// \itkcaption[SignedDanielssonDistanceMapImageFilter
// output]{SignedDanielssonDistanceMapImageFilter applied on a binary circle
// image. The intensity has been rescaled for purposes of display.}
// \label{fig:SignedDanielssonDistanceMapImageFilterInputOutput}
// \end{figure}
//
// Figure \ref{fig:SignedDanielssonDistanceMapImageFilterInputOutput}
// illustrates the effect of this filter. The input image and the distance
// map are shown.
//
// \index{Distance
// Map!itk::Signed\-Danielsson\-Distance\-Map\-Image\-Filter}
//
// Software Guide : EndLatex
return EXIT_SUCCESS;
}
itkImageFileReader.h
itkImage.h
itk::ImageFileReader
Data source that reads image data from a single file.
Definition: itkImageFileReader.h:75
itk::SignedDanielssonDistanceMapImageFilter
This filter computes the signed distance map of the input image as an approximation with pixel accura...
Definition: itkSignedDanielssonDistanceMapImageFilter.h:94
itk::ImageFileWriter
Writes image data to a single file.
Definition: itkImageFileWriter.h:87
itkRescaleIntensityImageFilter.h
itkImageFileWriter.h
itkSignedDanielssonDistanceMapImageFilter.h
itk::RescaleIntensityImageFilter
Applies a linear transformation to the intensity levels of the input Image.
Definition: itkRescaleIntensityImageFilter.h:154
itk::Image
Templated n-dimensional image class.
Definition: itkImage.h:86
itk::GTest::TypedefsAndConstructors::Dimension2::Dimension
constexpr unsigned int Dimension
Definition: itkGTestTypedefsAndConstructors.h:44