ITK/Examples/ImageProcessing/ThresholdImageFilter

This example demonstrates how to threshold an image using a ThresholdImageFilter, which offers few different types of thresholds. The output shows the original image and the thresholded image.

ThresholdImageFilter.cxx

<source lang="cpp">

1. include "itkImage.h"
2. include "itkThresholdImageFilter.h"
3. include "itkImageFileReader.h"

1. include "QuickView.h"

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

 if(argc < 2)
   {
   std::cerr << "Usage: ";
   std::cerr << argv[0] << " inputImageFile [lowerThreshold] [upperThreshold]" << std::endl;
   return EXIT_FAILURE;
   }

 int lowerThreshold = 10;
 int upperThreshold = 30;
 if (argc > 2)
   {
   lowerThreshold = atoi(argv[2]);
   }
 if (argc > 3)
   {
   upperThreshold = atoi(argv[3]);
   }

 typedef itk::Image<unsigned char, 2>    ImageType;
 typedef itk::ImageFileReader<ImageType> ReaderType;

 ReaderType::Pointer reader = ReaderType::New();
 reader->SetFileName(argv[1]);

 typedef itk::ThresholdImageFilter <ImageType>
   ThresholdImageFilterType;

 ThresholdImageFilterType::Pointer thresholdFilter
   = ThresholdImageFilterType::New();
 thresholdFilter->SetInput(reader->GetOutput());
 thresholdFilter->ThresholdOutside(lowerThreshold, upperThreshold);
 thresholdFilter->SetOutsideValue(0);

 QuickView viewer;
 viewer.AddImage<ImageType>(
   reader->GetOutput(),true,
   itksys::SystemTools::GetFilenameName(argv[1]));  
 std::stringstream desc;
 desc << "Threshold\nlower = " << lowerThreshold
      << " upper = " << upperThreshold;
 viewer.AddImage<ImageType>(
   thresholdFilter->GetOutput(),
   true,
   desc.str());
 viewer.Visualize();

 return EXIT_SUCCESS;

} </source>

CMakeLists.txt

<source lang="cmake"> cmake_minimum_required(VERSION 2.6)

PROJECT(ThresholdImageFilter)

include_directories(/home/doriad/src/ITK/Wrapping/WrapITK/ExternalProjects/ItkVtkGlue/src/)

FIND_PACKAGE(VTK REQUIRED) INCLUDE(${VTK_USE_FILE})

FIND_PACKAGE(ITK REQUIRED) INCLUDE(${ITK_USE_FILE})

ADD_EXECUTABLE(ThresholdImageFilter ThresholdImageFilter.cxx) TARGET_LINK_LIBRARIES(ThresholdImageFilter vtkHybrid ITKBasicFilters ITKCommon ITKIO)

</source>