GeometriesProjectionExample.cxx 5.76 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19
/*
 * 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.
 */
20 21 22 23


// Software Guide : BeginLatex
//
24 25 26
// Instead of using \doxygen{otb}{VectorData} to apply projections as
// explained in \ref{sec:VectorDataProjection}, we can also \emph{directly} work
// on OGR data types thanks to \doxygen{otb}{GeometriesProjectionFilter}.
27
//
28 29
// This example demonstrates how to proceed with this alternative set of vector
// data types.
30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49
//
// Software Guide : EndLatex

#include "otbGeometriesProjectionFilter.h"
#include "otbGeometriesSet.h"

#include "otbImage.h"
#include "otbImageFileReader.h"

int main(int argc, char* argv[])
{
  if (argc < 4)
    {
    std::cerr << argv[0] <<
    " <input vector filename> <input image name> <output vector filename>\n";
    return EXIT_FAILURE;
    }

  // Software Guide : BeginLatex
  //
50 51 52 53
  // Declare the geometries type that you would like to use in your
  // application. Unlike \doxygen{otb}{VectorData}, \doxygen{otb}{GeometriesSet}
  // is a single type for any kind of geometries set (OGR data source, or OGR
  // layer).
54 55 56 57 58 59 60 61 62 63
  //
  // Software Guide : EndLatex

  // Software Guide : BeginCodeSnippet
  typedef otb::GeometriesSet InputGeometriesType;
  typedef otb::GeometriesSet OutputGeometriesType;
  // Software Guide : EndCodeSnippet

  // Software Guide : BeginLatex
  //
64 65 66
  // First, declare and instantiate the data source
  // \subdoxygen{otb}{ogr}{DataSource}. Then, encapsulate this data source into
  // a \doxygen{otb}{GeometriesSet}.
67 68 69 70 71
  //
  // Software Guide : EndLatex

  // Software Guide : BeginCodeSnippet
  otb::ogr::DataSource::Pointer input = otb::ogr::DataSource::New(
72
    argv[1], otb::ogr::DataSource::Modes::Read);
73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95
  InputGeometriesType::Pointer in_set = InputGeometriesType::New(input);
  // Software Guide : EndCodeSnippet

  // Software Guide : BeginLatex
  //
  // We need the image only to retrieve its projection information,
  // i.e. map projection or sensor model parameters. Hence, the image
  // pixels won't be read, only the header information using the
  // \code{UpdateOutputInformation()} method.
  //
  // Software Guide : EndLatex

  // Software Guide : BeginCodeSnippet
  typedef otb::Image<unsigned short int, 2> ImageType;
  typedef otb::ImageFileReader<ImageType>   ImageReaderType;
  ImageReaderType::Pointer imageReader = ImageReaderType::New();
  imageReader->SetFileName(argv[2]);
  imageReader->UpdateOutputInformation();
  // Software Guide : EndCodeSnippet

  // Software Guide : BeginLatex
  //
  // The \doxygen{otb}{GeometriesProjectionFilter} will do the work of
96
  // converting the geometries coordinates. It is usually a good idea
97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126
  // to use it when you design applications reading or saving vector
  // data.
  //
  // Software Guide : EndLatex

  // Software Guide : BeginCodeSnippet
  typedef otb::GeometriesProjectionFilter GeometriesFilterType;
  GeometriesFilterType::Pointer filter = GeometriesFilterType::New();
  // Software Guide : EndCodeSnippet

  // Software Guide : BeginLatex
  //
  // Information concerning the original projection of the vector data
  // will be automatically retrieved from the metadata. Nothing else
  // is needed from you:
  //
  // Software Guide : EndLatex

  // Software Guide : BeginCodeSnippet
  filter->SetInput(in_set);
  // Software Guide : EndCodeSnippet

  // Software Guide : BeginLatex
  //
  // Information about the target projection is retrieved directly from
  // the image:
  //
  // Software Guide : EndLatex

  // Software Guide : BeginCodeSnippet
127 128 129 130 131
  // necessary for sensors
  filter->SetOutputKeywordList(imageReader->GetOutput()->GetImageKeywordlist());
  // necessary for sensors
  filter->SetOutputOrigin(imageReader->GetOutput()->GetOrigin());
  // necessary for sensors
132
  filter->SetOutputSpacing(imageReader->GetOutput()->GetSignedSpacing());
133 134
  // ~ wkt
  filter->SetOutputProjectionRef( imageReader->GetOutput()->GetProjectionRef());
135 136 137 138 139
  // Software Guide : EndCodeSnippet

  // Software Guide : BeginLatex
  //
  // Finally, the result is saved into a new vector file.
140 141 142 143 144 145
  // Unlike other OTB filters, \doxygen{otb}{GeometriesProjectionFilter} expects
  // to be given a valid output geometries set where to store the result of its
  // processing -- otherwise the result will be an in-memory data source, and
  // not stored in a file nor a data base.
  //
  // Then, the processing is started by calling \code{Update()}. The actual
146
  // serialization of the results is guaranteed to be completed when the output
147 148
  // geometries set object goes out of scope, or when \code{SyncToDisk} is
  // called.
149 150 151 152 153
  //
  // Software Guide : EndLatex

  // Software Guide : BeginCodeSnippet
  otb::ogr::DataSource::Pointer output = otb::ogr::DataSource::New(
154
    argv[3], otb::ogr::DataSource::Modes::Update_LayerCreateOnly);
155 156 157 158 159 160 161 162
  OutputGeometriesType::Pointer out_set = OutputGeometriesType::New(output);

  filter->SetOutput(out_set);
  filter->Update();
  // Software Guide : EndCodeSnippet

  // Software Guide : BeginLatex
  //
163 164 165
  // Once again, it is worth noting that none of this code is specific to the
  // vector data format. Whether you pass a shapefile, or a KML file, the
  // correct driver will be automatically instantiated.
166 167 168 169 170 171
  //
  // Software Guide : EndLatex

  return EXIT_SUCCESS;

}