Convert Array to Image

Synopsis

Convert a C-style array to an itkImage.

Results

Output Image.

Code

C++

#include "itkImage.h"
#include "itkImportImageFilter.h"

#include "itkImageFileWriter.h"

int
main(int, char *[])
{
  using PixelType = unsigned char;
  constexpr unsigned int Dimension = 3;
  using ImageType = itk::Image<PixelType, Dimension>;
  using ImportFilterType = itk::ImportImageFilter<PixelType, Dimension>;

  ImportFilterType::Pointer importFilter = ImportFilterType::New();

  ImportFilterType::SizeType size;

  size[0] = 200; // size along X
  size[1] = 200; // size along Y
  size[2] = 200; // size along Z

  ImportFilterType::IndexType start;
  start.Fill(0);

  ImportFilterType::RegionType region;
  region.SetIndex(start);
  region.SetSize(size);

  importFilter->SetRegion(region);

  double origin[Dimension];
  origin[0] = 0.0; // X coordinate
  origin[1] = 0.0; // Y coordinate
  origin[2] = 0.0; // Z coordinate

  importFilter->SetOrigin(origin);

  double spacing[Dimension];
  spacing[0] = 1.0; // along X direction
  spacing[1] = 1.0; // along Y direction
  spacing[2] = 1.0; // along Z direction

  importFilter->SetSpacing(spacing);

  const unsigned int numberOfPixels = size[0] * size[1] * size[2];
  auto *             localBuffer = new PixelType[numberOfPixels];

  constexpr double radius = 80.0;

  const double radius2 = radius * radius;
  PixelType *  it = localBuffer;

  for (unsigned int z = 0; z < size[2]; z++)
  {
    const double dz = static_cast<double>(z) - static_cast<double>(size[2]) / 2.0;
    for (unsigned int y = 0; y < size[1]; y++)
    {
      const double dy = static_cast<double>(y) - static_cast<double>(size[1]) / 2.0;
      for (unsigned int x = 0; x < size[0]; x++)
      {
        const double dx = static_cast<double>(x) - static_cast<double>(size[0]) / 2.0;
        const double d2 = dx * dx + dy * dy + dz * dz;
        *it++ = (d2 < radius2) ? 255 : 0;
      }
    }
  }

  const bool importImageFilterWillOwnTheBuffer = true;
  importFilter->SetImportPointer(localBuffer, numberOfPixels, importImageFilterWillOwnTheBuffer);

  using WriterType = itk::ImageFileWriter<ImageType>;
  WriterType::Pointer writer = WriterType::New();

  writer->SetFileName("test.png");

  writer->SetInput(importFilter->GetOutput());
  writer->Update();

  return EXIT_SUCCESS;
}

Classes demonstrated

template<typename TPixel, unsigned int VImageDimension = 2>
class ImportImageFilter : public itk::ImageSource<Image<TPixel, VImageDimension>>

Import data from a standard C array into an itk::Image.

ImportImageFilter provides a mechanism for importing data into an itk::Image. ImportImageFilter is an image source, so it behaves like any other pipeline object.

This class is templated over the pixel type and the image dimension of the output image.

ITK Sphinx Examples:

• All ITK Sphinx Examples

• Convert Array To Image

See itk::ImportImageFilter for additional documentation.