DOC: TileMapImageIO

Examples/IO/TileMapImageIOExample.cxx

@@ -25,6 +25,15 @@
 //    ${GeneratedFolder} 1.4835345  43.55968261 12
 //  Software Guide : EndCommandLineArgs
 
+
+// Software Guide : BeginLatex
+//
+// First, we need to include several headers. There will be a bit of
+// manual work going on here.
+//
+// Software Guide : EndLatex
+
+// Software Guide : BeginCodeSnippet
 #include "itkRGBPixel.h"
 #include "otbImage.h"
 #include "otbImageFileReader.h"
@@ -33,6 +42,7 @@
 #include "otbExtractROI.h"
 #include "otbImageFileWriter.h"
 #include "ossim/projection/ossimTileMapModel.h"
+// Software Guide : EndCodeSnippet
 
 int main( int argc, char* argv[] )
 {
@@ -47,14 +57,40 @@ int main( int argc, char* argv[] )
   }
 
 
-
+  // Software Guide : BeginLatex
+  //
+  // We retrieve the input parameters:
+  // \begin{itemize}
+  // \item the input filename is a simple text file specifying the access
+  // modality to open street map data;
+  // \item the output file is the image where you want to save the result;
+  // \item the cache directory is necessary to keep the data retrieved from
+  // the internet. It can also be reused to minimize network access;
+  // \item longitude of the center of the scene;
+  // \item latitude of the center of the scene;
+  // \item depth which is inversely related to the resolution: when you increase
+  // the depth by one, you divide the resolution by two.
+  // \end{itemize}
+  //
+  // Software Guide : EndLatex
+
+  // Software Guide : BeginCodeSnippet
   char * inputFilename = argv[1];
   char * outputFilename = argv[2];
   char * cacheDirectory = argv[3];
   double lon = atof(argv[4]);
   double lat = atof(argv[5]);
   int depth = atoi(argv[6]);
+  // Software Guide : EndCodeSnippet
+
+  // Software Guide : BeginLatex
+  //
+  // We now instanciate the reader. As some parameters need to be given to the
+  // IO which is an \doxygen{otb}{TileMapImageIO}, we need to manually create it also:
+  //
+  // Software Guide : EndLatex
 
+  // Software Guide : BeginCodeSnippet
   typedef itk::RGBPixel<unsigned char> RGBPixelType;
   typedef otb::Image<RGBPixelType, 2> ImageType;
   typedef otb::ImageFileReader<ImageType> ReaderType;
@@ -67,7 +103,22 @@ int main( int argc, char* argv[] )
   readerTile->SetImageIO(tileIO);
   readerTile->SetFileName(inputFilename);
   readerTile->UpdateOutputInformation();
-
+  // Software Guide : EndCodeSnippet
+
+  // Software Guide : BeginLatex
+  //
+  // Now, we potentially have an image of several Peta-bytes covering the whole world
+  // in the reader
+  // that's why we don't want to do an update before extracting a specific
+  // area.
+  //
+  // The coordinates are refered with an origin at the north pole and the
+  // change date meridian in Mercator projection. So we need to translate the latitude
+  // and the longitude in this funny coordinate system:
+  //
+  // Software Guide : EndLatex
+
+  // Software Guide : BeginCodeSnippet
   typedef otb::InverseSensorModel<double>  ModelType;
   ModelType::Pointer   model= ModelType::New();
 
@@ -79,6 +130,7 @@ int main( int argc, char* argv[] )
     return 1;
   }
 
+
   typedef itk::Point <double, 2> PointType;
   PointType lonLatPoint;
   lonLatPoint[0]=lon;
@@ -86,7 +138,16 @@ int main( int argc, char* argv[] )
 
   PointType tilePoint;
   tilePoint=model->TransformPoint(lonLatPoint);
+  // Software Guide : EndCodeSnippet
 
+  // Software Guide : BeginLatex
+  //
+  // This enable us to use the \doxygen{otb}{ExtractROI} to retrieve only
+  // the area of interest and to avoid crashing our memory-limited computer.
+  //
+  // Software Guide : EndLatex
+
+  // Software Guide : BeginCodeSnippet
   long int startX=static_cast<long int>(tilePoint[0]);
   long int startY=static_cast<long int>(tilePoint[1]);
   long int sizeX = 500;
@@ -103,14 +164,40 @@ int main( int argc, char* argv[] )
   extractROIOsmFilter->SetSizeY( sizeY );
 
   extractROIOsmFilter->SetInput(readerTile->GetOutput());
+  // Software Guide : EndCodeSnippet
 
+  // Software Guide : BeginLatex
+  //
+  // Finally, we just plug this to the writer to save our nice map of
+  // the area:
+  //
+  // Software Guide : EndLatex
 
-
+  // Software Guide : BeginCodeSnippet
   typedef otb::ImageFileWriter<ImageType> WriterType;
   WriterType::Pointer writer = WriterType::New();
   writer->SetFileName(outputFilename);
   writer->SetInput(extractROIOsmFilter->GetOutput());
   writer->Update();
+  // Software Guide : EndCodeSnippet
+
+
+  // Software Guide : BeginLatex
+  //
+  // Figure~\ref{fig:TILEMAPIMAGEIOEXAMPLE} shows the output images created from
+  // open street map data.
+  //
+  //
+  // \begin{figure}
+  // \center
+  // \includegraphics[width=0.70\textwidth]{openStreetMap.eps}
+  // \itkcaption[Open street map]{Map created from open street map at depth 12 near Toulouse}
+  // \label{fig:TILEMAPIMAGEIOEXAMPLE}
+  // \end{figure}
+  //
+  // If your street is missing, go and improve the map.
+  //
+  // Software Guide : EndLatex
 
   return EXIT_SUCCESS;