gradientFloatToInt.cpp

This code demonstrates how to adapt a float ImageView into a 16-bit unsigned integer ImageView.

This code demonstrates how to adapt a float ImageView into a 16-bit unsigned integer ImageView.Data are converted on the fly, and the resulting image has values between 0 and 65535. Both images are displayed to show their content.

#include <iomanip>
#include <iostream>
#include <vector>
 
#include <iolink/view/ImageViewFactory.h>
 
using namespace iolink;
 
// Create a a vertical gradient into a float ImageView
// using the given input range [min, max].
static std::shared_ptr<ImageView>
gradientFloatImage(const Vector2f& inputRange)
{
  const VectorXu64 shape = VectorXu64{5, 30};
 
  const DataType dt = DataTypeId::FLOAT;
 
  std::shared_ptr<ImageView> image = ImageViewFactory::allocate(shape, dt);
 
  std::vector<float> lineBuffer(shape[0]);
 
  const VectorXu64 lineSize{shape[0], 1};
 
  const float stepLine = (inputRange[1] - inputRange[0]) / shape[1];
 
  float valueInit = inputRange[0];
  float valueToSet = valueInit;
  for (size_t j = 0; j < shape[1]; ++j)
  {
    const RegionXu64 lineRegion(VectorXu64{0, j}, lineSize);
    std::fill(lineBuffer.begin(), lineBuffer.end(), valueToSet);
    image->writeRegion(lineRegion, lineBuffer.data());
    valueToSet = valueInit + j * stepLine;
  }
 
  return image;
}
 
// Display the content of an ImageView containing values of type T.
template <typename T>
static void
displayImageContent(std::shared_ptr<ImageView> image)
{
  const VectorXu64& shape = image->shape();
  RegionXu64 fullRegion = RegionXu64::createFullRegion(image->shape());
  std::vector<T> buffer(fullRegion.elementCount());
  image->readRegion(fullRegion, buffer.data());
 
  std::cout << "Image content: " << std::endl;
  for (size_t j = 0; j < shape[1]; ++j)
  {
    for (size_t i = 0; i < shape[0]; ++i)
    {
      std::cout << std::setw(6) << buffer[i + j * shape[0]] << " ";
    }
    std::cout << std::endl;
  }
  std::cout << std::endl;
}
 
int
main(int argc, char** argv)
{
  Vector2f range{0.0f, 5.0f};
 
  // create a float image containing a vertical gradient
  // with values between 0 and 5.0
  std::shared_ptr<ImageView> floatImage = gradientFloatImage(range);
 
  displayImageContent<float>(floatImage);
 
  // convert the float image to a 16-bit integer image
  // an adapter is added to the float image to convert the values on the fly
  // data are not duplicated
  std::shared_ptr<ImageView> imageInt =
    ImageViewFactory::adaptDynamicRange(floatImage,
                                        DataTypeId::UINT16,
                                        Vector2d(range),
                                        Vector2d{0, static_cast<double>(std::numeric_limits<uint16_t>().max())});
 
  displayImageContent<uint16_t>(imageInt);
 
  return EXIT_SUCCESS;
}