SphinxExamples/src/Filtering/ImageGrid/ResampleAVectorImage/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
 *
 *         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.
 *
 *=========================================================================*/
 
#include "itkImageFileReader.h"
#include "itkImageFileWriter.h"
#include "itkImage.h"
#include "itkResampleImageFilter.h"
#include "itkIdentityTransform.h"
#include "itkLinearInterpolateImageFunction.h"
#include "itkRGBPixel.h"
 
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];
 
  constexpr unsigned int Dimension = 2;
 
  using PixelComponentType = unsigned char;
  using PixelType = itk::RGBPixel<PixelComponentType>;
  using ImageType = itk::Image<PixelType, Dimension>;
 
  const auto input = itk::ReadImage<ImageType>(inputFileName);
 
  using FilterType = itk::ResampleImageFilter<ImageType, ImageType>;
 
  auto filter = FilterType::New();
 
  using InterpolatorType = itk::LinearInterpolateImageFunction<ImageType, double>;
 
  auto interpolator = InterpolatorType::New();
 
  filter->SetInterpolator(interpolator);
 
  using TransformType = itk::IdentityTransform<double, Dimension>;
  auto transform = TransformType::New();
 
  filter->SetTransform(transform);
 
  PixelType defaultValue;
  defaultValue.Fill(50);
  filter->SetDefaultPixelValue(defaultValue);
 
  ImageType::SpacingType spacing;
  spacing[0] = .5; // pixel spacing in millimeters along X
  spacing[1] = .5; // pixel spacing in millimeters along Y
 
  filter->SetOutputSpacing(spacing);
 
  ImageType::PointType origin;
  origin[0] = 30.0; // X space coordinate of origin
  origin[1] = 40.0; // Y space coordinate of origin
  filter->SetOutputOrigin(origin);
 
  ImageType::DirectionType direction;
  direction.SetIdentity();
  filter->SetOutputDirection(direction);
 
  ImageType::SizeType size;
 
  size[0] = 300; // number of pixels along X
  size[1] = 300; // number of pixels along Y
 
  filter->SetSize(size);
  filter->SetInput(input);
 
  try
  {
    itk::WriteImage(filter->GetOutput(), outputFileName);
  }
  catch (const itk::ExceptionObject & error)
  {
    std::cerr << "Error: " << error << std::endl;
    return EXIT_FAILURE;
  }
 
  return EXIT_SUCCESS;
}