ITK/Examples/Broken/EdgesAndGradients/CannyEdgeDetectionImageFilter: Difference between revisions

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(Created page with "How to set a reasonable Threshold for the output edges? ==CannyEdgeDetectionImageFilter.cxx== <source lang="cpp"> #include "itkImage.h" #include "itkImageFileReader.h" #include ...")
 
(Use QuickView)
Line 9: Line 9:
#include "itkCannyEdgeDetectionImageFilter.h"
#include "itkCannyEdgeDetectionImageFilter.h"


#include <itkImageToVTKImageFilter.h>
#include "QuickView.h"
 
#include "vtkImageViewer.h"
#include "vtkRenderWindowInteractor.h"
#include "vtkSmartPointer.h"
#include "vtkImageActor.h"
#include "vtkInteractorStyleImage.h"
#include "vtkRenderer.h"


int main(int argc, char *argv[])
int main(int argc, char *argv[])
Line 22: Line 15:
   if(argc < 2)
   if(argc < 2)
     {
     {
     std::cerr << "Required: filename" << std::endl;
     std::cerr << "Usage: " << argv[0]
              << " Filename [variance lower_threshold upper_threshold]"
              << std::endl;
     return EXIT_FAILURE;
     return EXIT_FAILURE;
     }
     }


   typedef itk::Image<unsigned char, 2> UnsignedCharImageType;
   double variance = 2.0;
   typedef itk::Image<float, 2>  FloatImageType;
  double upperThreshold = 0.0;
  double lowerThreshold = 0.0;
  if (argc > 2)
    {
    variance = atof(argv[2]);
    }
  if (argc > 3)
    {
    lowerThreshold = atof(argv[3]);
    }
  if (argc > 4)
    {
    upperThreshold = atof(argv[4]);
    }
 
   typedef itk::Image<double, 2>  DoubleImageType;


   typedef itk::ImageFileReader<UnsignedCharImageType> ReaderType;
   typedef itk::ImageFileReader<DoubleImageType> ReaderType;
   ReaderType::Pointer reader = ReaderType::New();
   ReaderType::Pointer reader = ReaderType::New();
   reader->SetFileName(argv[1]);
   reader->SetFileName(argv[1]);
  reader->Update();
  typedef itk::CastImageFilter< UnsignedCharImageType, FloatImageType > CastFilterType;
  CastFilterType::Pointer castFilter = CastFilterType::New();
  castFilter->SetInput(reader->GetOutput());


   typedef itk::CannyEdgeDetectionImageFilter <FloatImageType, FloatImageType>
   typedef itk::CannyEdgeDetectionImageFilter <DoubleImageType, DoubleImageType>
          CannyEdgeDetectionImageFilterType;
    CannyEdgeDetectionImageFilterType;


   CannyEdgeDetectionImageFilterType::Pointer cannyFilter
   CannyEdgeDetectionImageFilterType::Pointer cannyFilter
          = CannyEdgeDetectionImageFilterType::New();
    = CannyEdgeDetectionImageFilterType::New();
   cannyFilter->SetInput(castFilter->GetOutput());
   cannyFilter->SetInput(reader->GetOutput());
   cannyFilter->Update();
   cannyFilter->SetVariance( variance );
 
   cannyFilter->SetUpperThreshold( upperThreshold );
  typedef itk::CastImageFilter< FloatImageType, UnsignedCharImageType > OutputCastFilterType;
   cannyFilter->SetLowerThreshold( lowerThreshold );
  OutputCastFilterType::Pointer outputCastFilter = OutputCastFilterType::New();
   outputCastFilter->SetInput(cannyFilter->GetOutput());
 
   typedef itk::RescaleIntensityImageFilter< UnsignedCharImageType, UnsignedCharImageType > RescaleFilterType;
  RescaleFilterType::Pointer rescaleFilter = RescaleFilterType::New();
  rescaleFilter->SetInput(outputCastFilter->GetOutput());
  rescaleFilter->SetOutputMinimum(0);
  rescaleFilter->SetOutputMaximum(255);
 
  // Visualize first image
  typedef itk::ImageToVTKImageFilter<UnsignedCharImageType> ConnectorType;
  ConnectorType::Pointer originalConnector = ConnectorType::New();
  originalConnector->SetInput(reader->GetOutput());
 
  vtkSmartPointer<vtkImageActor> originalActor =
    vtkSmartPointer<vtkImageActor>::New();
  originalActor->SetInput(originalConnector->GetOutput());
 
  // Visualize edge image
  ConnectorType::Pointer cannyConnector = ConnectorType::New();
  cannyConnector->SetInput(rescaleFilter->GetOutput());
 
  vtkSmartPointer<vtkImageActor> cannyActor =
    vtkSmartPointer<vtkImageActor>::New();
  cannyActor->SetInput(cannyConnector->GetOutput());
 
  // There will be one render window
  vtkSmartPointer<vtkRenderWindow> renderWindow =
    vtkSmartPointer<vtkRenderWindow>::New();
  renderWindow->SetSize(600, 300);
 
  vtkSmartPointer<vtkRenderWindowInteractor> interactor =
    vtkSmartPointer<vtkRenderWindowInteractor>::New();
  interactor->SetRenderWindow(renderWindow);
 
  // Define viewport ranges
  // (xmin, ymin, xmax, ymax)
  double leftViewport[4] = {0.0, 0.0, 0.5, 1.0};
  double rightViewport[4] = {0.5, 0.0, 1.0, 1.0};
 
  // Setup both renderers
  vtkSmartPointer<vtkRenderer> leftRenderer =
    vtkSmartPointer<vtkRenderer>::New();
  renderWindow->AddRenderer(leftRenderer);
  leftRenderer->SetViewport(leftViewport);
  leftRenderer->SetBackground(.6, .5, .4);
 
  vtkSmartPointer<vtkRenderer> rightRenderer =
    vtkSmartPointer<vtkRenderer>::New();
  renderWindow->AddRenderer(rightRenderer);
  rightRenderer->SetViewport(rightViewport);
  rightRenderer->SetBackground(.4, .5, .6);
 
  // Add the sphere to the left and the cube to the right
  leftRenderer->AddActor(originalActor);
  rightRenderer->AddActor(cannyActor);
 
  leftRenderer->ResetCamera();
  rightRenderer->ResetCamera();
 
  renderWindow->Render();


   vtkSmartPointer<vtkInteractorStyleImage> style =
   QuickView viewer;
    vtkSmartPointer<vtkInteractorStyleImage>::New();
  viewer.AddImage<DoubleImageType>(reader->GetOutput());
   interactor->SetInteractorStyle(style);
   viewer.AddImage<DoubleImageType>(cannyFilter->GetOutput());
 
   viewer.Visualize();
   interactor->Start();


   return EXIT_SUCCESS;
   return EXIT_SUCCESS;
}
}
</source>
</source>


Revision as of 00:32, 18 November 2010

How to set a reasonable Threshold for the output edges?

CannyEdgeDetectionImageFilter.cxx

<source lang="cpp">

  1. include "itkImage.h"
  2. include "itkImageFileReader.h"
  3. include "itkRescaleIntensityImageFilter.h"
  4. include "itkCastImageFilter.h"
  5. include "itkCannyEdgeDetectionImageFilter.h"
  1. include "QuickView.h"

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

 if(argc < 2)
   {
   std::cerr << "Usage: " << argv[0]
             << " Filename [variance lower_threshold upper_threshold]"
             << std::endl;
   return EXIT_FAILURE;
   }

 double variance = 2.0;
 double upperThreshold = 0.0;
 double lowerThreshold = 0.0;
 if (argc > 2)
   {
   variance = atof(argv[2]);
   }
 if (argc > 3)
   {
   lowerThreshold = atof(argv[3]);
   }
 if (argc > 4)
   {
   upperThreshold = atof(argv[4]);
   }

 typedef itk::Image<double, 2>  DoubleImageType;

 typedef itk::ImageFileReader<DoubleImageType> ReaderType;
 ReaderType::Pointer reader = ReaderType::New();
 reader->SetFileName(argv[1]);

 typedef itk::CannyEdgeDetectionImageFilter <DoubleImageType, DoubleImageType>
   CannyEdgeDetectionImageFilterType;

 CannyEdgeDetectionImageFilterType::Pointer cannyFilter
   = CannyEdgeDetectionImageFilterType::New();
 cannyFilter->SetInput(reader->GetOutput());
 cannyFilter->SetVariance( variance );
 cannyFilter->SetUpperThreshold( upperThreshold );
 cannyFilter->SetLowerThreshold( lowerThreshold );

 QuickView viewer;
 viewer.AddImage<DoubleImageType>(reader->GetOutput());
 viewer.AddImage<DoubleImageType>(cannyFilter->GetOutput());
 viewer.Visualize();

 return EXIT_SUCCESS;

} </source>

CMakeLists.txt

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

PROJECT(CannyEdgeDetectionImageFilter)

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(CannyEdgeDetectionImageFilter CannyEdgeDetectionImageFilter.cxx) TARGET_LINK_LIBRARIES(CannyEdgeDetectionImageFilter vtkHybrid ITKBasicFilters ITKCommon ITKIO)

</source>

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