BandMathFilterExample.cxx

/*
 * Copyright (C) 2005-2019 Centre National d'Etudes Spatiales (CNES)
 *
 * This file is part of Orfeo Toolbox
 *
 *     https://www.orfeo-toolbox.org/
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/* Example usage:
./BandMathFilterExample Input/qb_RoadExtract.tif Output/RoadExtractBandMath.tif Output/qb_BandMath-pretty.jpg
*/

#include "itkMacro.h"
#include <iostream>

#include "otbImage.h"
#include "otbVectorImage.h"
#include "otbImageFileReader.h"
#include "otbImageFileWriter.h"
#include "itkUnaryFunctorImageFilter.h"
#include "itkCastImageFilter.h"
#include "otbVectorImageToImageListFilter.h"

// We start by including the required header file.
// The aim of this example is to compute the Normalized Difference Vegetation Index (NDVI)
// from a multispectral image and then apply a threshold to this
// index to extract areas containing a dense vegetation canopy.
#include "otbBandMathImageFilter.h"

int main(int argc, char* argv[])
{
  if (argc != 4)
  {
    std::cerr << "Usage: " << argv[0] << " inputImageFile ";
    std::cerr << " outputImageFile ";
    std::cerr << " outputPrettyImageFile" << std::endl;
    return EXIT_FAILURE;
  }

  // We start by the typedefs needed for reading and
  // writing the images. The BandMathImageFilter class
  // works with Image as input, so we need to define additional
  // filters to extract each layer of the multispectral image.
  typedef double                                                           PixelType;
  typedef otb::VectorImage<PixelType, 2>                                   InputImageType;
  typedef otb::Image<PixelType, 2>                                         OutputImageType;
  typedef otb::ImageList<OutputImageType>                                  ImageListType;
  typedef otb::VectorImageToImageListFilter<InputImageType, ImageListType> VectorImageToImageListType;
  typedef otb::ImageFileReader<InputImageType>                             ReaderType;
  typedef otb::ImageFileWriter<OutputImageType>                            WriterType;

  // We can now define the type for the filter
  typedef otb::BandMathImageFilter<OutputImageType> FilterType;

  // We instantiate the filter, the reader, and the writer
  ReaderType::Pointer reader = ReaderType::New();
  WriterType::Pointer writer = WriterType::New();
  FilterType::Pointer filter = FilterType::New();