Examples/Filtering/VectorIndexSelection.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.
 *
 *=========================================================================*/
 
// Software Guide : BeginCodeSnippet
#include "itkImageFileReader.h"
#include "itkImageFileWriter.h"
#include "itkVectorIndexSelectionCastImageFilter.h"
#include "itkRGBPixel.h"
 
// Software Guide : EndCodeSnippet
 
 
#include "itkImage.h"
 
 
int
main(int argc, char * argv[])
{
  // Verify the number of parameters in the command line
  if (argc < 4)
  {
    std::cerr << "Usage: " << std::endl;
    std::cerr << argv[0] << " inputImageFile  outputImageFile component"
              << std::endl;
    return EXIT_FAILURE;
  }
 
 
  // Software Guide : BeginCodeSnippet
  using InputPixelType = itk::RGBPixel<unsigned char>;
  using OutputPixelType = unsigned char;
  constexpr unsigned int Dimension = 2;
 
  using InputImageType = itk::Image<InputPixelType, Dimension>;
  using OutputImageType = itk::Image<OutputPixelType, Dimension>;
  // Software Guide : EndCodeSnippet
 
 
  // Software Guide : BeginCodeSnippet
  using ReaderType = itk::ImageFileReader<InputImageType>;
  using FilterType =
    itk::VectorIndexSelectionCastImageFilter<InputImageType, OutputImageType>;
  using WriterType = itk::ImageFileWriter<OutputImageType>;
  // Software Guide : EndCodeSnippet
 
 
  // Software Guide : BeginCodeSnippet
  auto filter = FilterType::New();
  filter->SetIndex(std::stoi(argv[3]));
  // Software Guide : EndCodeSnippet
 
 
  //  Software Guide : BeginLatex
  //
  //  Then, we create the reader and writer and connect the pipeline.
  //
  //  \index{itk::ImageFileReader!New()}
  //  \index{itk::ImageFileWriter!New()}
  //  \index{itk::ImageFileReader!SmartPointer}
  //  \index{itk::ImageFileWriter!SmartPointer}
  //
  //  Software Guide : EndLatex
 
  // Software Guide : BeginCodeSnippet
  auto reader = ReaderType::New();
  auto writer = WriterType::New();
 
  filter->SetInput(reader->GetOutput());
  writer->SetInput(filter->GetOutput());
  // Software Guide : EndCodeSnippet
 
 
  //
  // Here we recover the file names from the command line arguments
  //
  const char * inputFilename = argv[1];
  const char * outputFilename = argv[2];
 
 
  // Software Guide : BeginCodeSnippet
  reader->SetFileName(inputFilename);
  writer->SetFileName(outputFilename);
  // Software Guide : EndCodeSnippet
 
 
  //  Software Guide : BeginLatex
  //
  //  Finally we trigger the execution of the pipeline with the Update()
  //  method on the writer. The output image will then be the scaled and cast
  //  version of the input image.
  //
  //  Software Guide : EndLatex
 
 
  // Software Guide : BeginCodeSnippet
  try
  {
    writer->Update();
  }
  catch (const itk::ExceptionObject & err)
  {
    std::cout << "ExceptionObject caught !" << std::endl;
    std::cout << err << std::endl;
    return EXIT_FAILURE;
  }
  // Software Guide : EndCodeSnippet
 
 
  return EXIT_SUCCESS;
}