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/*
* Copyright (C) 2005-2017 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.
*/
// Software Guide : BeginCommandLineArgs
// OUTPUTS: {mapProjectionExample-output.txt}
// Software Guide : EndCommandLineArgs
// Software Guide : BeginLatex
//
// Map projection is an important issue when working with satellite
// images. In the orthorectification process, converting between
// geographic and cartographic coordinates is a key step. In this
// process, everything is integrated and you don't need to know the
// details.
//
// However, sometimes, you need to go hands-on and find out the
// nitty-gritty details. This example shows you how to play with map
// projections in OTB and how to convert coordinates. In most cases,
// the underlying work is done by OSSIM.
//
// First, we start by including the otbMapProjections header. In this
// file, over 30 projections are defined and ready to use. It is easy
// to add new one.
//
// The otbGenericMapProjection enables you to instantiate a map
// projection from a WKT (Well Known Text) string, which is popular
// with OGR for example.
//
// Software Guide : EndLatex
#include <fstream>
#include <iomanip>
// Software Guide : BeginCodeSnippet
#include "otbMapProjections.h"
#include "otbGenericMapProjection.h"
// Software Guide : EndCodeSnippet
int main(int argc, char* argv[])
{
if (argc < 2)
{
std::cout << argv[0] << " <outputfile> " << std::endl;
return EXIT_FAILURE;
}
// Software Guide : BeginLatex
//
// We retrieve the command line parameters and put them in the
// correct variables. The transforms are going to work with an
// \doxygen{itk}{Point}.
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
const char * outFileName = argv[1];
itk::Point<double, 2> point;
point[0] = 1.4835345;
point[1] = 43.55968261;
// Software Guide : EndCodeSnippet
// Software Guide : BeginLatex
//
// The output of this program will be saved in a text file. We also want
// to make sure that the precision of the digits will be enough.
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
std::ofstream file;
file.open(outFileName);
file << std::setprecision(15);
// Software Guide : EndCodeSnippet
// Software Guide : BeginLatex
//
// We can now instantiate our first map projection. Here, it is a
// UTM projection. We also need to provide the information about
// the zone and the hemisphere for the projection. These are
// specific to the UTM projection.
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
otb::UtmForwardProjection::Pointer utmProjection
= otb::UtmForwardProjection::New();
utmProjection->SetZone(31);
utmProjection->SetHemisphere('N');
// Software Guide : EndCodeSnippet
// Software Guide : BeginLatex
//
// The TransformPoint() method returns the coordinates of the point in the
// new projection.
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
file << "Forward UTM projection: " << std::endl;
file << point << " -> ";
file << utmProjection->TransformPoint(point);
file << std::endl << std::endl;
// Software Guide : EndCodeSnippet
// Software Guide : BeginLatex
//
// We follow the same path for the Lambert93 projection:
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
otb::Lambert93ForwardProjection::Pointer lambertProjection
= otb::Lambert93ForwardProjection::New();
file << "Forward Lambert93 projection: " << std::endl;
file << point << " -> ";
file << lambertProjection->TransformPoint(point);
file << std::endl << std::endl;
// Software Guide : EndCodeSnippet
// Software Guide : BeginLatex
//
// If you followed carefully the previous examples, you've noticed
// that the target projections have been directly coded, which means
// that they can't be changed at run-time. What happens if you don't
// know the target projection when you're writing the program? It
// can depend on some input provided by the user (image,
// shapefile).
//
// In this situation, you can use the
// \doxygen{otb}{GenericMapProjection}. It will accept a string to
// set the projection. This string should be in the WKT format.
//
// For example:
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
std::string projectionRefWkt = "PROJCS[\"UTM Zone 31, Northern Hemisphere\","
"GEOGCS[\"WGS 84\", DATUM[\"WGS_1984\", SPHEROID[\"WGS 84\", 6378137, 298.257223563,"
"AUTHORITY[\"EPSG\",\"7030\"]], TOWGS84[0, 0, 0, 0, 0, 0, 0],"
"AUTHORITY[\"EPSG\",\"6326\"]], PRIMEM[\"Greenwich\", 0, AUTHORITY[\"EPSG\",\"8901\"]],"
"UNIT[\"degree\", 0.0174532925199433, AUTHORITY[\"EPSG\",\"9108\"]],"
"AXIS[\"Lat\", NORTH], AXIS[\"Long\", EAST],"
"AUTHORITY[\"EPSG\",\"4326\"]], PROJECTION[\"Transverse_Mercator\"],"
"PARAMETER[\"latitude_of_origin\", 0], PARAMETER[\"central_meridian\", 3],"
"PARAMETER[\"scale_factor\", 0.9996], PARAMETER[\"false_easting\", 500000],"
"PARAMETER[\"false_northing\", 0], UNIT[\"Meter\", 1]]";
// Software Guide : EndCodeSnippet
// Software Guide : BeginLatex
//
// This string is then passed to the projection using the
// \code{SetWkt()} method.
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
typedef otb::GenericMapProjection<otb::TransformDirection::FORWARD> GenericMapProjection;
GenericMapProjection::Pointer genericMapProjection =
GenericMapProjection::New();
genericMapProjection->SetWkt(projectionRefWkt);
file << "Forward generic projection: " << std::endl;
file << point << " -> ";
file << genericMapProjection->TransformPoint(point);
file << std::endl << std::endl;
// Software Guide : EndCodeSnippet
// Software Guide : BeginLatex
//
// And of course, we don't forget to close the file:
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
file.close();
// Software Guide : EndCodeSnippet
// Software Guide : BeginLatex
//
// The final output of the program should be:
//
// \begin{verbatim}
// Forward UTM projection:
// [1.4835345, 43.55968261] -> [377522.448427013, 4824086.71129131]
//
// Forward Lambert93 projection:
// [1.4835345, 43.55968261] -> [577437.889798954, 6274578.791561]
//
// Forward generic projection:
// [1.4835345, 43.55968261] -> [377522.448427013, 4824086.71129131]
// \end{verbatim}
//
// Software Guide : EndLatex
return EXIT_SUCCESS;
}
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