ITK  4.8.0
Insight Segmentation and Registration Toolkit
SphinxExamples/src/Filtering/FFT/ComputeImageSpectralDensity/Code.cxx
int main( int argc, char* argv[] )
{
if( argc != 3 )
{
std::cerr << "Usage: "<< std::endl;
std::cerr << argv[0];
std::cerr << " <InputFileName> <OutputFileName>";
std::cerr << std::endl;
return EXIT_FAILURE;
}
const char * inputFileName = argv[1];
const char * outputFileName = argv[2];
const unsigned int Dimension = 3;
typedef float PixelType;
typedef itk::Image< PixelType, Dimension > RealImageType;
ReaderType::Pointer reader = ReaderType::New();
reader->SetFileName( inputFileName );
// Some FFT filter implementations, like VNL's, need the image size to be a
// multiple of small prime numbers.
PadFilterType::Pointer padFilter = PadFilterType::New();
padFilter->SetInput( reader->GetOutput() );
PadFilterType::SizeType padding;
// Input size is [48, 62, 42]. Pad to [48, 64, 48].
padding[0] = 0;
padding[1] = 2;
padding[2] = 6;
padFilter->SetPadUpperBound( padding );
typedef itk::ForwardFFTImageFilter< RealImageType > ForwardFFTFilterType;
typedef ForwardFFTFilterType::OutputImageType ComplexImageType;
ForwardFFTFilterType::Pointer forwardFFTFilter = ForwardFFTFilterType::New();
forwardFFTFilter->SetInput( padFilter->GetOutput() );
ComplexToModulusFilterType;
ComplexToModulusFilterType::Pointer complexToModulusFilter
= ComplexToModulusFilterType::New();
complexToModulusFilter->SetInput( forwardFFTFilter->GetOutput() );
// Window and shift the output for visualization.
typedef unsigned short OutputPixelType;
WindowingFilterType;
WindowingFilterType::Pointer windowingFilter
= WindowingFilterType::New();
windowingFilter->SetInput( complexToModulusFilter->GetOutput() );
windowingFilter->SetWindowMinimum( 0 );
windowingFilter->SetWindowMaximum( 20000 );
FFTShiftFilterType::Pointer fftShiftFilter = FFTShiftFilterType::New();
fftShiftFilter->SetInput( windowingFilter->GetOutput() );
WriterType::Pointer writer = WriterType::New();
writer->SetFileName( outputFileName );
writer->SetInput( fftShiftFilter->GetOutput() );
try
{
writer->Update();
}
catch( itk::ExceptionObject & error )
{
std::cerr << "Error: " << error << std::endl;
return EXIT_FAILURE;
}
return EXIT_SUCCESS;
}