SphinxExamples/src/Core/Common/MakeOutOfBoundsPixelsReturnConstValue/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 "itkImage.h"
#include "itkConstNeighborhoodIterator.h"
#include "itkConstantBoundaryCondition.h"
#include "itkImageRegionIterator.h"
 
#include <itkImageToVTKImageFilter.h>
 
#include "vtkVersion.h"
#include "vtkImageViewer.h"
#include "vtkImageMapper3D.h"
#include "vtkRenderWindowInteractor.h"
#include "vtkSmartPointer.h"
#include "vtkImageActor.h"
#include "vtkInteractorStyleImage.h"
#include "vtkRenderer.h"
 
using ImageType = itk::Image<unsigned char, 2>;
static void
CreateImage(ImageType::Pointer image);
 
int
main()
{
  auto image = ImageType::New();
  CreateImage(image);
 
  ImageType::SizeType regionSize;
  regionSize[0] = 50;
  regionSize[1] = 1;
 
  ImageType::IndexType regionIndex;
  regionIndex[0] = 0;
  regionIndex[1] = 0;
 
  ImageType::RegionType region;
  region.SetSize(regionSize);
  region.SetIndex(regionIndex);
 
  ImageType::SizeType radius;
  radius[0] = 1;
  radius[1] = 1;
 
  using BoundaryConditionType = itk::ConstantBoundaryCondition<ImageType>;
  itk::ConstNeighborhoodIterator<ImageType, BoundaryConditionType> iterator(radius, image, region);
 
  while (!iterator.IsAtEnd())
  {
    for (unsigned int i = 0; i < 9; ++i)
    {
      ImageType::IndexType index = iterator.GetIndex(i);
 
      std::cout << "Index: " << index << " Pixel: " << i << " = " << (int)iterator.GetPixel(i) << std::endl;
    }
    ++iterator;
  }
 
  // Visualize
  using ConnectorType = itk::ImageToVTKImageFilter<ImageType>;
  auto connector = ConnectorType::New();
  connector->SetInput(image);
 
  vtkSmartPointer<vtkImageActor> actor = vtkSmartPointer<vtkImageActor>::New();
#if VTK_MAJOR_VERSION <= 5
  actor->SetInput(connector->GetOutput());
#else
  connector->Update();
  actor->GetMapper()->SetInputData(connector->GetOutput());
#endif
 
  vtkSmartPointer<vtkRenderWindow> renderWindow = vtkSmartPointer<vtkRenderWindow>::New();
 
  vtkSmartPointer<vtkRenderWindowInteractor> interactor = vtkSmartPointer<vtkRenderWindowInteractor>::New();
  interactor->SetRenderWindow(renderWindow);
 
  vtkSmartPointer<vtkRenderer> renderer = vtkSmartPointer<vtkRenderer>::New();
  renderWindow->AddRenderer(renderer);
 
  renderer->AddActor(actor);
  renderer->ResetCamera();
 
  renderWindow->Render();
 
  vtkSmartPointer<vtkInteractorStyleImage> style = vtkSmartPointer<vtkInteractorStyleImage>::New();
 
  interactor->SetInteractorStyle(style);
 
  interactor->Start();
 
  return EXIT_SUCCESS;
}
 
void
CreateImage(ImageType::Pointer image)
{
  // Create an image with 2 connected components
  ImageType::RegionType region;
  ImageType::IndexType  start;
  start[0] = 0;
  start[1] = 0;
 
  ImageType::SizeType size;
  unsigned int        NumRows = 5;
  unsigned int        NumCols = 5;
  size[0] = NumRows;
  size[1] = NumCols;
 
  region.SetSize(size);
  region.SetIndex(start);
 
  image->SetRegions(region);
  image->Allocate();
 
  itk::ImageRegionIterator<ImageType> imageIterator(image, region);
 
  // Set all pixels to white
  while (!imageIterator.IsAtEnd())
  {
    imageIterator.Set(255);
    ++imageIterator;
  }
}