TextureExample.cxx

Fig. 14 Result of applying the ScalarImageToTexturesFilter to an image (contrast).

Example usage:

./TextureExample Input/ADS40RoiSmall.png Output/TextureOutput.tif Output/pretty_TextureOutput.png 2 1 1

Example source code (TextureExample.cxx):

#include "itkMacro.h"
#include "otbImage.h"
#include "otbImageFileReader.h"
#include "otbImageFileWriter.h"

// Pretty RGB output
#include "otbVectorImage.h"
#include "otbImageToVectorImageCastFilter.h"
#include "otbVectorRescaleIntensityImageFilter.h"

#include "otbScalarImageToTexturesFilter.h"

int main(int argc, char* argv[])
{
  // Parse command line parameters
  if (argc != 7)
  {
    std::cerr << "Usage: " << argv[0] << " <inputImage> ";
    std::cerr << " <outputImage> <outputRescaled> ";
    std::cerr << " <radius> <xOffset> <yOffset> ";
    std::cerr << std::endl;
    return EXIT_FAILURE;
  }

  const char* infname        = argv[1];
  const char* outfname       = argv[2];
  const char* outprettyfname = argv[3];

  const unsigned int radius  = static_cast<unsigned int>(atoi(argv[4]));
  const unsigned int xOffset = static_cast<unsigned int>(atoi(argv[5]));
  const unsigned int yOffset = static_cast<unsigned int>(atoi(argv[6]));

  using PixelType     = double;
  const int Dimension = 2;
  using ImageType     = otb::Image<PixelType, Dimension>;

  // After defining the types for the pixels and the images used in the
  // example, we define the types for the textures filter. It is
  // templated by the input and output image types.
  using TexturesFilterType = otb::ScalarImageToTexturesFilter<ImageType, ImageType>;
  using ReaderType         = otb::ImageFileReader<ImageType>;
  using WriterType         = otb::ImageFileWriter<ImageType>;

  ReaderType::Pointer reader = ReaderType::New();
  WriterType::Pointer writer = WriterType::New();

  reader->SetFileName(infname);
  writer->SetFileName(outfname);

  // We can now instantiate the filters.
  TexturesFilterType::Pointer texturesFilter = TexturesFilterType::New();

  // The texture filters takes at least 2 parameters: the radius of the
  // neighborhood on which the texture will be computed and the offset
  // used. Texture features are bivariate statistics, that is, they are
  // computed using pair of pixels. Each texture feature is defined for
  // an offset defining the pixel pair.
  //
  // The radius parameter can be passed to the filter as a scalar
  // parameter if the neighborhood is square, or as \code{SizeType} in
  // any case.
  //
  // The offset is always an array of N values, where N is the number of
  // dimensions of the image.

  using SizeType = ImageType::SizeType;
  SizeType sradius;
  sradius.Fill(radius);

  texturesFilter->SetRadius(sradius);

  using OffsetType = ImageType::OffsetType;
  OffsetType offset;
  offset[0] = xOffset;
  offset[1] = yOffset;

  texturesFilter->SetOffset(offset);

  // The textures filter will automatically derive the optimal
  // bin size for co-occurences histogram, but they need to know
  // the input image minimum and maximum. These values can be set
  // like this :

  texturesFilter->SetInputImageMinimum(0);
  texturesFilter->SetInputImageMaximum(255);

  // To tune co-occurence histogram resolution, you can use
  // the SetNumberOfBinsPerAxis() method.

  // We can now plug the pipeline.
  texturesFilter->SetInput(reader->GetOutput());
  writer->SetInput(texturesFilter->GetInertiaOutput());
  writer->Update();

  // Pretty image creation for printing
  using VectorImageType        = otb::VectorImage<double, 2>;
  using PrettyVectorImageType  = otb::VectorImage<unsigned char, 2>;
  using WriterPrettyOutputType = otb::ImageFileWriter<PrettyVectorImageType>;

  using VectorCastFilterType = otb::ImageToVectorImageCastFilter<ImageType, VectorImageType>;
  using RescalerOutputType   = otb::VectorRescaleIntensityImageFilter<VectorImageType, PrettyVectorImageType>;

  RescalerOutputType::Pointer     outputRescaler     = RescalerOutputType::New();
  WriterPrettyOutputType::Pointer prettyOutputWriter = WriterPrettyOutputType::New();
  VectorCastFilterType::Pointer   vectorCastFilter   = VectorCastFilterType::New();
  vectorCastFilter->SetInput(texturesFilter->GetInertiaOutput());
  outputRescaler->SetInput(vectorCastFilter->GetOutput());

  PrettyVectorImageType::PixelType min(1), max(1);
  min.Fill(0);
  max.Fill(255);

  outputRescaler->SetOutputMinimum(min);
  outputRescaler->SetOutputMaximum(max);

  prettyOutputWriter->SetFileName(outprettyfname);
  prettyOutputWriter->SetInput(outputRescaler->GetOutput());

  prettyOutputWriter->Update();
}