SphinxExamples/src/IO/ImageBase/ConvertImageToAnotherType/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 "itkRGBPixel.h"
#include "itkRGBAPixel.h"
#include "itkImage.h"
#include "itkDefaultConvertPixelTraits.h"
#include "itkConvertPixelBuffer.h"
#include "itkImageRandomConstIteratorWithIndex.h"
 
int
main()
{
  constexpr int xDimension = 200;
  constexpr int yDimension = 100;
 
  using ComponentType = unsigned char;
  using RGBPixelType = itk::RGBPixel<ComponentType>;
  using RGBAPixelType = itk::RGBAPixel<ComponentType>;
  using RGBImageType = itk::Image<RGBPixelType, 2>;
  using RGBAImageType = itk::Image<RGBAPixelType, 2>;
  using TraitsType = itk::DefaultConvertPixelTraits<RGBPixelType>;
  using RGBAConverterType = itk::ConvertPixelBuffer<ComponentType, RGBPixelType, TraitsType>;
 
  auto rgbImg = RGBImageType::New();
  auto rgbaImg = RGBAImageType::New();
 
  // Create the two images
  // RGBAImage
  RGBAImageType::IndexType rgbaStart;
  rgbaStart[0] = 0;
  rgbaStart[1] = 0;
 
  RGBAImageType::SizeType rgbaSize;
  rgbaSize[0] = xDimension;
  rgbaSize[1] = yDimension;
 
  itk::ImageRegion<2> rgbaRegion(rgbaStart, rgbaSize);
  rgbaImg->SetRegions(rgbaRegion);
  rgbaImg->Allocate();
 
  RGBAPixelType rgbaDefault;
  rgbaDefault[0] = 127;
  rgbaDefault[1] = 100;
  rgbaDefault[2] = 230;
  rgbaDefault[3] = 255;
  rgbaImg->FillBuffer(rgbaDefault);
 
  // RGBImage
  itk::ImageRegion<2> rgbRegion = rgbaRegion;
  rgbImg->SetRegions(rgbRegion);
  rgbImg->Allocate();
 
  size_t numberOfPixels = rgbImg->GetLargestPossibleRegion().GetNumberOfPixels();
 
  // Convert a raw buffer to a buffer of pixel types
  RGBAConverterType::Convert(rgbaImg->GetBufferPointer()->GetDataPointer(),
                             rgbaImg->GetNumberOfComponentsPerPixel(),
                             rgbImg->GetBufferPointer(),
                             numberOfPixels);
 
  // Check a few random values
  itk::ImageRandomConstIteratorWithIndex<RGBImageType> rgbIterator(rgbImg, rgbImg->GetLargestPossibleRegion());
  rgbIterator.SetNumberOfSamples(numberOfPixels / 10);
  rgbIterator.GoToBegin();
 
  while (!rgbIterator.IsAtEnd())
  {
    if (rgbImg->GetPixel(rgbIterator.GetIndex())[0] != rgbaImg->GetPixel(rgbIterator.GetIndex())[0] ||
 
        rgbImg->GetPixel(rgbIterator.GetIndex())[1] != rgbaImg->GetPixel(rgbIterator.GetIndex())[1] ||
 
        rgbImg->GetPixel(rgbIterator.GetIndex())[2] != rgbaImg->GetPixel(rgbIterator.GetIndex())[2])
    {
      std::cout << "Copy failed for index " << rgbIterator.GetIndex() << " got "
                << rgbImg->GetPixel(rgbIterator.GetIndex()) << " but expected "
                << rgbaImg->GetPixel(rgbIterator.GetIndex()) << std::endl;
    }
    ++rgbIterator;
  }
  return EXIT_SUCCESS;
}