gradientFloatImage.cpp

This code demonstrates how to create a vertical gradient image with values between 0.0 and 5.0.

This code demonstrates how to create a vertical gradient image with values between 0.0 and 5.0.Lines are written one by one from the bottom to the top.

#include <iomanip>
#include <iostream>
#include <vector>
 
#include <iolink/view/ImageViewFactory.h>
 
using namespace iolink;
 
std::shared_ptr<ImageView>
gradientFloatImage(const VectorXu64& shape)
{
  // To create a float ImageView, the datatype of the image can be FLOAT (32bits) or DOUBLE (64 bits)
  const DataType dt = DataTypeId::FLOAT;
 
  // create an image view in CPU memory
  std::shared_ptr<ImageView> image = ImageViewFactory::allocate(shape, dt);
 
  // create a buffer to write a line of data
  // this buffer is float-typed to match the image datatype
  std::vector<float> lineBuffer(shape[0]);
 
  // define the size of the line to write
  const VectorXu64 lineSize{shape[0], 1};
 
  std::cout << "Writing data line by line" << std::endl;
 
  // define the step between two values in the gradient
  const float stepLine = 5.0f / shape[1];
 
  // write data line by line with a growing value
  float valueInit = 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;
  }
 
  std::cout << "Writing completed" << std::endl;
 
  return image;
}
 
// Display the content of a float ImageView.
static void
displayImageContent(std::shared_ptr<ImageView> image)
{
  const VectorXu64& shape = image->shape();
  RegionXu64 fullRegion = RegionXu64::createFullRegion(image->shape());
  std::vector<float> 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(8) << buffer[i + j * shape[0]] << " ";
    }
    std::cout << std::endl;
  }
  std::cout << std::endl;
}
 
int
main(int argc, char** argv)
{
  std::shared_ptr<ImageView> image = gradientFloatImage({5, 30});
 
  std::cout << "Shape of created image: " << image->shape() << std::endl;
 
  displayImageContent(image);
 
  return EXIT_SUCCESS;
}