OTB  6.7.0
Orfeo Toolbox
IO/DEMToImageGenerator.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:
./DEMToImageGenerator Output/DEMToImageGenerator.tif Output/pretty_DEMToImageGenerator.png 6.5 45.5 500 500 0.002 -0.002 Input/DEM_srtm
*/
// \index{otb::DEMToImageGenerator}
// \index{otb::DEMHandler}
//
//
// The following example illustrates the use of the \doxygen{otb}{DEMToImageGenerator} class.
// The aim of this class is to generate an image from the srtm data (precising the start extraction
// latitude and longitude point). Each pixel is a geographic point and its intensity is
// the altitude of the point.
// If srtm doesn't have altitude information for a point, the altitude value is set at -32768 (value of the srtm norm).
//
// Let's look at the minimal code required to use this algorithm. First, the following header
// defining the \doxygen{otb}{DEMToImageGenerator} class must be included.
#include "itkMacro.h"
int main(int argc, char* argv[])
{
if (argc < 10)
{
std::cout << argv[0]
<< " output filename , pretty output filename , Longitude Output Origin point , Latitude Output Origin point , X Output Size, Y Output size , X "
"Spacing , Y Spacing, DEM folder path"
<< std::endl;
return EXIT_FAILURE;
}
// The image type is now defined using pixel type and
// dimension. The output image is defined as an \doxygen{otb}{Image}.
char* folderPath = argv[9];
char* outputName = argv[1];
const unsigned int Dimension = 2;
using ImageType = otb::Image<double, Dimension>;
// The writer is defined
using WriterType = otb::ImageFileWriter<ImageType>;
// The DEMToImageGenerator is defined using the image pixel
// type as a template parameter. After that, the object can be instancied.
using DEMToImageGeneratorType = otb::DEMToImageGenerator<ImageType>;
DEMToImageGeneratorType::Pointer object = DEMToImageGeneratorType::New();
// Input parameter types are defined to set the value in the \doxygen{otb}{DEMToImageGenerator}.
// Instantiating writer
WriterType::Pointer writer = WriterType::New();
// The path to the DEM folder is given to the \doxygen{otb}{DEMHandler}.
otb::DEMHandler::Instance()->OpenDEMDirectory(folderPath);
// The origin (Longitude/Latitude) of the output image in the DEM is given to the filter.
PointType origin;
origin[0] = ::atof(argv[3]);
origin[1] = ::atof(argv[4]);
object->SetOutputOrigin(origin);
// The size (in Pixel) of the output image is given to the filter.
SizeType size;
size[0] = ::atoi(argv[5]);
size[1] = ::atoi(argv[6]);
object->SetOutputSize(size);
// The spacing (step between to consecutive pixel) is given to the filter.
// By default, this spacing is set at 0.001.
SpacingType spacing;
spacing[0] = ::atof(argv[7]);
spacing[1] = ::atof(argv[8]);
object->SetOutputSpacing(spacing);
// The output image name is given to the writer and
// the filter output is linked to the writer input.
writer->SetFileName(outputName);
writer->SetInput(object->GetOutput());
// The invocation of the \code{Update()} method on the writer triggers the
// execution of the pipeline. It is recommended to place update calls in a
// \code{try/catch} block in case errors occur and exceptions are thrown.
try
{
writer->Update();
}
catch (itk::ExceptionObject& err)
{
std::cout << "Exception itk::ExceptionObject thrown !" << std::endl;
std::cout << err << std::endl;
return EXIT_FAILURE;
}
catch (...)
{
std::cout << "Unknown exception thrown !" << std::endl;
return EXIT_FAILURE;
}
// Pretty image creation for the printing
using OutputPrettyImageType = otb::Image<unsigned char, Dimension>;
using ThresholderType = itk::ThresholdImageFilter<ImageType>;
ThresholderType::Pointer thresholder = ThresholderType::New();
RescalerType::Pointer rescaler = RescalerType::New();
WriterPrettyType::Pointer prettyWriter = WriterPrettyType::New();
thresholder->SetInput(object->GetOutput());
thresholder->SetOutsideValue(0.0);
thresholder->ThresholdBelow(0.0);
thresholder->Update();
rescaler->SetInput(thresholder->GetOutput());
rescaler->SetOutputMinimum(0);
rescaler->SetOutputMaximum(255);
prettyWriter->SetFileName(argv[2]);
prettyWriter->SetInput(rescaler->GetOutput());
try
{
prettyWriter->Update();
}
catch (itk::ExceptionObject& excep)
{
std::cerr << "Exception caught !" << std::endl;
std::cerr << excep << std::endl;
}
catch (...)
{
std::cout << "Unknown exception !" << std::endl;
return EXIT_FAILURE;
}
return EXIT_SUCCESS;
// Let's now run this example using as input the SRTM data contained in
// \code{DEM\_srtm} folder. Figure \ref{fig:DEMToImageGenerator}
// shows the obtained DEM. Invalid data values -- hidden areas due
// to SAR shadowing -- are set to zero.
//
//
// \begin{figure} \center
// \includegraphics[width=0.24\textwidth]{pretty_DEMToImageGenerator.eps}
// \itkcaption[DEM To Image generator Example]{DEMToImageGenerator image.}
// \label{fig:DEMToImageGenerator}
// \end{figure}
}