ITK/Examples/EdgesAndGradients/GradientMagnitudeImageFilter

GradientMagnitudeImageFilter.cxx

<source lang="cpp">

1. include <string>

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

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

 // Verify command line arguments
 if( argc < 3 )
   {

std::cerr << "Usage: " << std::endl; std::cerr << argv[0] << " inputImageFile outputImageFile " << std::endl; return EXIT_FAILURE;

   }

 // Parse command line arguments
 std::string inputFilename = argv[1];
 std::string outputFilename = argv[2];

 // Setup types
 typedef    float    inputPixelType;
 typedef    float    outputPixelType;

 typedef itk::Image< inputPixelType,  2 >   inputImageType;
 typedef itk::Image< outputPixelType, 2 >   outputImageType;

 typedef itk::ImageFileReader< inputImageType >  readerType;

 typedef itk::GradientMagnitudeImageFilter<

inputImageType, outputImageType > 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();

 // To write the gradient image file, we must rescale the gradient values
 // to a reasonable range
 typedef unsigned char writePixelType;
 typedef itk::Image< writePixelType, 2 > writeImageType;
 typedef itk::RescaleIntensityImageFilter<

outputImageType, writeImageType > rescaleFilterType;

 rescaleFilterType::Pointer rescaler = rescaleFilterType::New();
 rescaler->SetOutputMinimum(   0 );
 rescaler->SetOutputMaximum( 255 );
 rescaler->SetInput( gradientFilter->GetOutput() );

 // Create and setup a writer
 typedef itk::ImageFileWriter< writeImageType >  writerType;
 writerType::Pointer writer = writerType::New();
 writer->SetFileName( outputFilename.c_str() );
 writer->SetInput( rescaler->GetOutput() );
 writer->Update();

 return 0;

} </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 ITKNumerics ITKIO ITKAlgorithms)

</source>