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/*=========================================================================
*
* Copyright Insight Software Consortium
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0.txt
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*=========================================================================*/
#include <iostream>
#include "itkChangeInformationImageFilter.h"
#include "itkHalfToFullHermitianImageFilter.h"
#include "itkRandomImageSource.h"
#include "itkRealToHalfHermitianForwardFFTImageFilter.h"
int itkHalfToFullHermitianImageFilterTest(int argc, char *argv[])
{
// Print usage information.
if ( argc < 3 )
{
std::cerr << "Usage: " << argv[0] << " <test image size x> <test image size y>"
<< std::endl;
return EXIT_FAILURE;
}
// Read in image.
typedef itk::Image< float, 2 > ImageType;
typedef itk::Image< std::complex< float >, 2 > ComplexImageType;
typedef itk::RandomImageSource< ImageType > RandomSourceType;
RandomSourceType::Pointer source = RandomSourceType::New();
RandomSourceType::SizeType size;
size[0] = atoi( argv[1] );
size[1] = atoi( argv[2] );
source->SetMin( 0.0f );
source->SetMax( 1.0f );
source->SetSize( size );
source->Update();
// Change the index of the image's largest possible region to test
// generality of the filters.
typedef itk::ChangeInformationImageFilter< ImageType > ChangeFilterType;
ChangeFilterType::Pointer changer = ChangeFilterType::New();
changer->ChangeRegionOn();
ChangeFilterType::OutputImageOffsetValueType indexShift[2];
indexShift[0] = -3;
indexShift[1] = 5;
changer->SetOutputOffset( indexShift );
changer->SetInput( source->GetOutput() );
// Compute frequency image, yielding the non-redundant half of the
// full complex image.
typedef itk::RealToHalfHermitianForwardFFTImageFilter< ImageType, ComplexImageType > FFTFilter;
FFTFilter::Pointer fft = FFTFilter::New();
fft->SetInput( changer->GetOutput() );
// Expand the non-redundant half to the full complex image.
typedef itk::HalfToFullHermitianImageFilter< ComplexImageType > HalfToFullFilterType;
HalfToFullFilterType::Pointer halfToFullFilter = HalfToFullFilterType::New();
halfToFullFilter->SetActualXDimensionIsOdd( fft->GetActualXDimensionIsOddOutput() );
halfToFullFilter->SetInput( fft->GetOutput() );
halfToFullFilter->Update();
halfToFullFilter->Print(std::cout);
ComplexImageType::SizeType fftSize = fft->GetOutput()->GetLargestPossibleRegion().GetSize();
// Test that the output is the expected size.
ComplexImageType::RegionType halfToFullOutputRegion =
halfToFullFilter->GetOutput()->GetLargestPossibleRegion();
ComplexImageType::SizeType halfToFullOutputSize = halfToFullOutputRegion.GetSize();
if ( halfToFullOutputSize != size )
{
std::cerr << "HalfToFullHermitianImageFilter did not produce an image of the expected size. "
<< std::endl;
std::cerr << "Expected size " << size << ", output size is " << halfToFullOutputSize
<< std::endl;
return EXIT_FAILURE;
}
// Test that the full image has the Hermitian property.
ComplexImageType::IndexType conjugateRegionIndex;
conjugateRegionIndex.Fill( 0 );
conjugateRegionIndex[0] = static_cast< ComplexImageType::IndexValueType >( fftSize[0] ) +
indexShift[0];
conjugateRegionIndex[1] = indexShift[1];
ComplexImageType::SizeType conjugateRegionSize( size );
conjugateRegionSize[0] -= fftSize[0];
itk::ImageRegion< ComplexImageType::ImageDimension > conjugateRegion( conjugateRegionIndex,
conjugateRegionSize );
typedef itk::ImageRegionConstIteratorWithIndex< ComplexImageType > ComplexIteratorType;
ComplexIteratorType it( halfToFullFilter->GetOutput(), conjugateRegion );
for (it.GoToBegin(); !it.IsAtEnd(); ++it)
{
ComplexImageType::IndexType conjugateIndex = it.GetIndex();
// Flip the indices about the center of the image.
ComplexImageType::IndexType index( conjugateIndex );
for (unsigned int i = 0; i < ComplexImageType::ImageDimension; ++i)
{
if ( conjugateIndex[i] != indexShift[i] )
{
index[i] = size[i] - conjugateIndex[i] + 2*indexShift[i];
}
}
if ( it.Get() != std::conj( halfToFullFilter->GetOutput()->GetPixel( index ) ) )
{
std::cerr << std::endl << "Mismatch found in conjugate index " << conjugateIndex
<< " (original index " << index << "). Expected "
<< std::conj( halfToFullFilter->GetOutput()->GetPixel( index ) )
<< ", got " << it.Get() << "." << std::endl;
return EXIT_FAILURE;
}
}
return EXIT_SUCCESS;
}
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