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

#include "itkImage.h"
#include "itkImageFileReader.h"
#include "itkImageFileWriter.h"
#include "itkRescaleIntensityImageFilter.h"
#include "itkGradientMagnitudeImageFilter.h"

#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;
}

CMakeLists.txt

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)