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/*=========================================================================
*
* 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
*
* https://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.
*
*=========================================================================*/
// Software Guide : BeginLatex
//
// Resampling can also be performed in multi-component images.
// This example compares nearest neighbor resampling using the Nearest
// neighbor and the linear interpolators for vector images.
//
// Try
// ResampleImageFilter9 Examples/Data/VisibleWomanEyeSlice.png
// SliceNearestNeighbor.png SliceLinear.png
//
// \index{itk::ResampleImageFilter!Image internal transform}
//
// Software Guide : EndLatex
#include "itkImage.h"
#include "itkImageFileReader.h"
#include "itkImageFileWriter.h"
#include "itkResampleImageFilter.h"
#include "itkIdentityTransform.h"
#include "itkNearestNeighborInterpolateImageFunction.h"
#include "itkLinearInterpolateImageFunction.h"
#include "itkRGBPixel.h"
int
main(int argc, char * argv[])
{
if (argc < 4)
{
std::cerr << "Usage: " << std::endl;
std::cerr << argv[0]
<< " inputImageFile outputImageFile_NearestNeighbor"
<< " outputImageFile_Linear " << std::endl;
return EXIT_FAILURE;
}
constexpr unsigned int Dimension = 2;
using PixelComponentType = unsigned char;
using PixelType = itk::RGBPixel<PixelComponentType>;
using ImageType = itk::Image<PixelType, Dimension>;
using ReaderType = itk::ImageFileReader<ImageType>;
using WriterType = itk::ImageFileWriter<ImageType>;
auto reader = ReaderType::New();
auto writerNearest = WriterType::New(); // writer for nearest neighbor
auto writerLinear = WriterType::New(); // writer for linear
reader->SetFileName(argv[1]);
writerNearest->SetFileName(argv[2]);
writerLinear->SetFileName(argv[3]);
using FilterType = itk::ResampleImageFilter<ImageType, ImageType>;
auto nearestFilter = FilterType::New();
auto linearFilter = FilterType::New();
// Interpolators
using NearestInterpolatorType =
itk::NearestNeighborInterpolateImageFunction<ImageType, double>;
auto interpolatorNearest = NearestInterpolatorType::New();
using LinearInterpolatorType =
itk::LinearInterpolateImageFunction<ImageType, double>;
auto interpolatorLinear = LinearInterpolatorType::New();
nearestFilter->SetInterpolator(interpolatorNearest);
linearFilter->SetInterpolator(interpolatorLinear);
using TransformType = itk::IdentityTransform<double, Dimension>;
auto transform = TransformType::New();
nearestFilter->SetTransform(transform);
linearFilter->SetTransform(transform);
// Software Guide : BeginCodeSnippet
PixelType defaultValue;
defaultValue.Fill(50);
nearestFilter->SetDefaultPixelValue(defaultValue);
linearFilter->SetDefaultPixelValue(defaultValue);
// Software Guide : EndCodeSnippet
// Software Guide : BeginCodeSnippet
ImageType::SpacingType spacing;
spacing[0] = .35; // pixel spacing in millimeters along X
spacing[1] = .35; // pixel spacing in millimeters along Y
nearestFilter->SetOutputSpacing(spacing);
linearFilter->SetOutputSpacing(spacing);
// Software Guide : EndCodeSnippet
// Software Guide : BeginCodeSnippet
ImageType::PointType origin;
origin[0] = 0.4; // X space coordinate of origin
origin[1] = 0.4; // Y space coordinate of origin
nearestFilter->SetOutputOrigin(origin);
linearFilter->SetOutputOrigin(origin);
// Software Guide : EndCodeSnippet
// Software Guide : BeginCodeSnippet
ImageType::DirectionType direction;
direction.SetIdentity();
nearestFilter->SetOutputDirection(direction);
linearFilter->SetOutputDirection(direction);
// Software Guide : EndCodeSnippet
ImageType::SizeType size;
size[0] = 300; // number of pixels along X
size[1] = 300; // number of pixels along Y
nearestFilter->SetSize(size);
linearFilter->SetSize(size);
nearestFilter->SetInput(reader->GetOutput());
linearFilter->SetInput(reader->GetOutput());
writerNearest->SetInput(nearestFilter->GetOutput());
writerLinear->SetInput(linearFilter->GetOutput());
try
{
writerNearest->Update();
}
catch (const itk::ExceptionObject & excp)
{
std::cerr << "Exception thrown " << std::endl;
std::cerr << excp << std::endl;
}
try
{
writerLinear->Update();
}
catch (const itk::ExceptionObject & excp)
{
std::cerr << "Exception thrown " << std::endl;
std::cerr << excp << std::endl;
}
return EXIT_SUCCESS;
}
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