ITK/Examples/EdgesAndGradients/GradientMagnitudeImageFilter

This example demonstrates how to compute the magnitude of the gradient of an image. The original image and an image of the gradient magnitude are displayed.

GradientMagnitudeImageFilter.cxx

<source lang="cpp">

1. include "itkImage.h"
2. include "itkImageFileReader.h"
3. include "itkImageFileWriter.h"
4. include "itkRescaleIntensityImageFilter.h"
5. include "itkGradientMagnitudeImageFilter.h"

1. include "QuickView.h"

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

 // Verify command line arguments
 if( argc < 2 )
   {
   std::cerr << "Usage: " << std::endl;
   std::cerr << argv[0] << " inputImageFile" << std::endl;
   return EXIT_FAILURE;
   }

 // Parse command line arguments
 std::string inputFilename = argv[1];

 // Setup types
 typedef itk::Image< unsigned char,  2 >  UnsignedCharImageType;
 typedef itk::Image< float,  2 >   FloatImageType;
 typedef itk::ImageFileReader< UnsignedCharImageType >  readerType;

 typedef itk::GradientMagnitudeImageFilter<

UnsignedCharImageType, FloatImageType > filterType;

 // Create and setup a reader
 readerType::Pointer reader = readerType::New();
 reader->SetFileName( inputFilename.c_str() );

 // Create and setup a gradient filter
 filterType::Pointer gradientFilter = filterType::New();
 gradientFilter->SetInput( reader->GetOutput() );
 gradientFilter->Update();

 QuickView viewer;
 viewer.AddImage<UnsignedCharImageType>(reader->GetOutput());
 viewer.AddImage<FloatImageType>(gradientFilter->GetOutput());
 viewer.Visualize();

 return EXIT_SUCCESS;

} </source>

CMakeLists.txt

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

PROJECT(GradientMagnitudeImageFilter)

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

ADD_EXECUTABLE(GradientMagnitudeImageFilter GradientMagnitudeImageFilter.cxx) TARGET_LINK_LIBRARIES(Gradient vtkHybrid ITKBasicFilters ITKIO ITKCommon) </source>