ITK  5.3.0
Insight Toolkit
SphinxExamples/src/Core/ImageFunction/ResampleSegmentedImage/Code.cxx
/*=========================================================================
*
* Copyright NumFOCUS
*
* 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 "itkImage.h"
int
main(int argc, char * argv[])
{
if (argc != 6)
{
std::cerr << "Usage: " << argv[0]
<< " inputImageFile spacingFraction sigmaFraction outputImageFileLabelImageInterpolator "
"outputImageFileNearestNeighborInterpolator"
<< std::endl;
return EXIT_FAILURE;
}
const char * const inputImageFile = argv[1];
const double spacingFraction = std::stod(argv[2]);
const double sigmaFraction = std::stod(argv[3]);
const char * const outputImageFileLabelImageInterpolator = argv[4];
const char * const outputImageFileNearestNeighborInterpolator = argv[5];
constexpr unsigned int Dimension = 2;
using PixelType = unsigned char;
const auto input = itk::ReadImage<ImageType>(inputImageFile);
ResampleFilterType::Pointer resizeFilter = ResampleFilterType::New();
resizeFilter->SetInput(input);
// Compute and set the output size
//
// The computation must be so that the following holds:
//
// new width old x spacing
// ---------- = ---------------
// old width new x spacing
//
//
// new height old y spacing
// ------------ = ---------------
// old height new y spacing
//
// So either we specify new height and width and compute new spacings
// or we specify new spacing and compute new height and width
// and computations that follows need to be modified a little (as it is
const ImageType::SpacingType inputSpacing{ input->GetSpacing() };
ImageType::SpacingType outputSpacing;
for (unsigned int dim = 0; dim < Dimension; ++dim)
{
outputSpacing[dim] = inputSpacing[dim] * spacingFraction;
}
resizeFilter->SetOutputSpacing(outputSpacing);
const ImageType::RegionType inputRegion{ input->GetLargestPossibleRegion() };
const ImageType::SizeType inputSize{ inputRegion.GetSize() };
ImageType::SizeType outputSize;
for (unsigned int dim = 0; dim < Dimension; ++dim)
{
outputSize[dim] = inputSize[dim] * inputSpacing[dim] / spacingFraction;
}
resizeFilter->SetSize(outputSize);
GaussianInterpolatorType::Pointer gaussianInterpolator = GaussianInterpolatorType::New();
GaussianInterpolatorType::ArrayType sigma;
for (unsigned int dim = 0; dim < Dimension; ++dim)
{
sigma[dim] = outputSpacing[dim] * sigmaFraction;
}
gaussianInterpolator->SetSigma(sigma);
gaussianInterpolator->SetAlpha(3.0);
resizeFilter->SetInterpolator(gaussianInterpolator);
try
{
itk::WriteImage(resizeFilter->GetOutput(), outputImageFileLabelImageInterpolator, true); // compress
}
catch (itk::ExceptionObject & error)
{
std::cerr << "Error: " << error << std::endl;
return EXIT_FAILURE;
}
using NearestNeighborInterpolatorType = itk::NearestNeighborInterpolateImageFunction<ImageType, double>;
NearestNeighborInterpolatorType::Pointer nearestNeighborInterpolator = NearestNeighborInterpolatorType::New();
resizeFilter->SetInterpolator(nearestNeighborInterpolator);
try
{
itk::WriteImage(resizeFilter->GetOutput(), outputImageFileNearestNeighborInterpolator, true); // compress
}
catch (itk::ExceptionObject & error)
{
std::cerr << "Error: " << error << std::endl;
return EXIT_FAILURE;
}
return EXIT_SUCCESS;
}
itkImageFileReader.h
itk::GTest::TypedefsAndConstructors::Dimension2::SizeType
ImageBaseType::SizeType SizeType
Definition: itkGTestTypedefsAndConstructors.h:49
itkImage.h
itk::GTest::TypedefsAndConstructors::Dimension2::RegionType
ImageBaseType::RegionType RegionType
Definition: itkGTestTypedefsAndConstructors.h:54
itkNearestNeighborInterpolateImageFunction.h
itkImageFileWriter.h
itk::Size::SetSize
void SetSize(const SizeValueType val[VDimension])
Definition: itkSize.h:179
itkLabelImageGaussianInterpolateImageFunction.h
itk::ResampleImageFilter
Resample an image via a coordinate transform.
Definition: itkResampleImageFilter.h:90
itk::Image
Templated n-dimensional image class.
Definition: itkImage.h:88
itk::NearestNeighborInterpolateImageFunction
Nearest neighbor interpolation of a scalar image.
Definition: itkNearestNeighborInterpolateImageFunction.h:39
itkResampleImageFilter.h
itk::GTest::TypedefsAndConstructors::Dimension2::Dimension
constexpr unsigned int Dimension
Definition: itkGTestTypedefsAndConstructors.h:44
itk::WriteImage
ITK_TEMPLATE_EXPORT void WriteImage(TImagePointer &&image, const std::string &filename, bool compress=false)
Definition: itkImageFileWriter.h:254
itk::LabelImageGaussianInterpolateImageFunction
Interpolation function for multi-label images that implicitly smooths each unique value in the image ...
Definition: itkLabelImageGaussianInterpolateImageFunction.h:72
itk::Size::GetSize
const SizeValueType * GetSize() const
Definition: itkSize.h:169