RGB Images

#include "itkImage.h"
#include "itkImageFileReader.h"
#include "itkRGBPixel.h"

int
main(int, char* argv[])
{

    using PixelType = itk::RGBPixel<unsigned char>;
    using ImageType = itk::Image<PixelType, 3>;
    using ReaderType = itk::ImageFileReader<ImageType>;

    ReaderType::Pointer reader = ReaderType::New();
    const char* const  filename = argv[1];
    reader->SetFileName(filename);
    reader->Update();

    ImageType::Pointer         image = reader->GetOutput();
    const ImageType::IndexType pixelIndex = { { 25, 35, 0 } };

    PixelType onePixel = image->GetPixel(pixelIndex);

    PixelType::ValueType red = onePixel.GetRed();
    PixelType::ValueType green = onePixel.GetGreen();
    PixelType::ValueType blue = onePixel.GetBlue();
    // Software Guide : EndCodeSnippet

    std::cout << "Pixel values from GetRed,GetGreen,GetBlue:" << std::endl;
    std::cout << "Red = "
        << itk::NumericTraits<PixelType::ValueType>::PrintType(red)
        << std::endl;
    std::cout << "Green = "
        << itk::NumericTraits<PixelType::ValueType>::PrintType(green)
        << std::endl;
    std::cout << "Blue = "
        << itk::NumericTraits<PixelType::ValueType>::PrintType(blue)
        << std::endl;

    red = onePixel[0];   // extract Red   component
    green = onePixel[1]; // extract Green component
    blue = onePixel[2];  // extract Blue  component

    std::cout << "Pixel values:" << std::endl;
    std::cout << "Red = "
        << itk::NumericTraits<PixelType::ValueType>::PrintType(red)
        << std::endl;
    std::cout << "Green = "
        << itk::NumericTraits<PixelType::ValueType>::PrintType(green)
        << std::endl;
    std::cout << "Blue = "
        << itk::NumericTraits<PixelType::ValueType>::PrintType(blue)
        << std::endl;
    return EXIT_SUCCESS;
}