DOC: Adding an example for the rasterization filter

Examples/Filtering/CMakeLists.txt

@@ -60,6 +60,9 @@ ADD_EXECUTABLE(DanielssonDistanceMapImageFilter DanielssonDistanceMapImageFilter
 TARGET_LINK_LIBRARIES(DanielssonDistanceMapImageFilter OTBCommon OTBIO
 ITKCommon ITKBasicFilters)
 
+ADD_EXECUTABLE(RasterizationExample RasterizationExample.cxx)
+TARGET_LINK_LIBRARIES(RasterizationExample OTBCommon OTBIO OTBBasicFilters)
+
 IF( NOT OTB_DISABLE_CXX_TESTING AND BUILD_TESTING )
 
 

Examples/Filtering/RasterizationExample.cxx

+/*=========================================================================
+
+  Program:   ORFEO Toolbox
+  Language:  C++
+  Date:      $Date$
+  Version:   $Revision$
+
+
+  Copyright (c) Centre National d'Etudes Spatiales. All rights reserved.
+  See OTBCopyright.txt for details.
+
+
+     This software is distributed WITHOUT ANY WARRANTY; without even
+     the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
+     PURPOSE.  See the above copyright notices for more information.
+
+=========================================================================*/
+#if defined(_MSC_VER)
+#pragma warning ( disable : 4786 )
+#endif
+
+//  Software Guide : BeginCommandLineArgs
+//    INPUTS: {w002n44e.shp}
+//    OUTPUTS: {ArcachonRasterizedCoastline.png}
+//  Software Guide : EndCommandLineArgs
+
+// Software Guide : BeginLatex
+//
+// The \doxygen{otb}{VectorDataToImageFilter} allows to perform
+// rasterization of a given vector data as a binary mask. This example
+// will demonstrate how to use this filter to perform rasterization of
+// the SRTM water body masks available here:
+// \url{http://dds.cr.usgs.gov/srtm/version2_1/SWBD/}.
+//
+// First step to use this filter is to include the appropriate headers:
+// 
+// Software Guide : EndLatex
+
+// Software Guide : BeginCodeSnippet
+#include "otbVectorData.h"
+#include "otbImage.h"
+#include "otbVectorDataToImageFilter.h"
+// Software Guide : EndCodeSnippet
+
+#include "otbImageFileWriter.h"
+#include "otbVectorDataExtractROI.h"
+#include "otbVectorDataProjectionFilter.h"
+#include "itkRGBAPixel.h"
+#include "itkChangeLabelImageFilter.h"
+#include "otbVectorDataFileReader.h"
+
+int main(int argc, char * argv[])
+{
+  // Software Guide : BeginLatex
+  // 
+  // Then, we need to define the appropriate VectorData and Image
+  // type.
+  // 
+  // Software Guide : EndLatex
+
+  // Software Guide : BeginCodeSnippet
+  
+  typedef unsigned char                 PixelType;
+  typedef otb::Image<PixelType, 2>      ImageType;
+  typedef otb::VectorData<>             VectorDataType;
+
+  // Software Guide : EndCodeSnippet
+
+  // Software Guide : BeginLatex
+  //
+  // Using these typedefs, we can define and instantiate the
+  // \doxygen{otb}{VectorDataToImageFilter}.
+  //
+  // Software Guide : EndLatex
+
+  // Software Guide : BeginCodeSnippet
+
+  typedef otb::VectorDataToImageFilter<VectorDataType, 
+    ImageType>            VectorDataToImageFilterType;
+  VectorDataToImageFilterType::Pointer vectorDataRendering 
+    = VectorDataToImageFilterType::New();
+
+  // Software Guide : EndCodeSnippet
+
+  // Software Guide : BeginLatex
+  //
+  // We will also define a \doxygen{otb}{VectorDataFileReader} to read
+  // the VectorData, as well as a
+  // \doxygen{otb}{VectorDataProjectionFilter} to reproject our data
+  // in a given map projection.
+  //
+  // Software Guide : EndLatex
+
+  // Software Guide : BeginCodeSnippet
+
+  typedef otb::VectorDataFileReader<VectorDataType> VectorDataFileReaderType;
+  VectorDataFileReaderType::Pointer reader = VectorDataFileReaderType::New();
+  reader->SetFileName(argv[1]);
+
+  typedef otb::VectorDataProjectionFilter<VectorDataType, 
+    VectorDataType> ProjectionFilterType;
+  ProjectionFilterType::Pointer projection = ProjectionFilterType::New();
+  projection->SetInput(reader->GetOutput());
+
+  // Software Guide : EndCodeSnippet
+
+  std::string projectionRefWkt = "PROJCS[\"WGS 84 / UTM zone 30N\",GEOGCS[\"WGS 84\",DATUM[\"WGS_1984\",SPHEROID[\"WGS 84\",6378137,298.257223563,AUTHORITY[\"EPSG\",\"7030\"]],AUTHORITY[\"EPSG\",\"6326\"]],PRIMEM[\"Greenwich\",0,AUTHORITY[\"EPSG\",\"8901\"]],UNIT[\"degree\",0.01745329251994328,AUTHORITY[\"EPSG\",\"9122\"]],AUTHORITY[\"EPSG\",\"4326\"]],UNIT[\"metre\",1,AUTHORITY[\"EPSG\",\"9001\"]],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],AUTHORITY[\"EPSG\",\"32630\"],AXIS[\"Easting\",EAST],AXIS[\"Northing\",NORTH]]";
+
+  // Software Guide : BeginLatex
+  // 
+  // Next step is to specify the map projection in which to reproject
+  // our vector.
+  //
+  // Software Guide : EndLatex
+
+  // Software Guide : BeginCodeSnippet
+  
+  projection->SetOutputProjectionRef(projectionRefWkt);
+
+  // Software Guide : EndCodeSnippet
+
+  // Software Guide : BeginLatex
+  //
+  // Since the input vector can be pretty big, we will perform an
+  // extract of the region of interest using the
+  // \doxygen{otb}{VectorDataExtractROI}.
+  //
+  // The first step is to define the region of interest.
+  //
+  // Software Guide : EndLatex
+
+  // Software Guide : BeginCodeSnippet
+  typedef otb::RemoteSensingRegion<double> RegionType;
+  ImageType::SizeType size;
+  size[0] = 500;
+  size[1] = 500;
+
+  ImageType::PointType origin;
+  origin[0] = 633602; //UL easting
+  origin[1] = 4961679; //UL northing
+
+  ImageType::SpacingType spacing;
+  spacing[0] = 56;
+  spacing[1] = -56;
+
+  RegionType region;
+  RegionType::SizeType sizeInUnit;
+  sizeInUnit[0] = size[0] * spacing[0];
+  sizeInUnit[1] = size[1] * spacing[1];
+  region.SetSize(sizeInUnit);
+  region.SetOrigin(origin);
+  region.SetRegionProjection(projectionRefWkt);
+  
+  // Software Guide : EndCodeSnippet
+
+  // Software Guide : BeginLatex
+  //
+  // Then, we define and set-up the
+  // \doxygen{otb}{VectorDataExtractROI} filter using the region.
+  //
+  // Software Guide : EndLatex
+
+  // Software Guide :: BeginCodeSnippet
+
+  typedef otb::VectorDataExtractROI<VectorDataType> ExtractROIType;
+  ExtractROIType::Pointer extractROI = ExtractROIType::New();
+  extractROI->SetRegion(region);
+  extractROI->SetInput(projection->GetOutput());
+
+  // Software Guide : EndCodeSnippet
+
+  // Software Guide : BeginLatex
+  //
+  // Now, we can plug the the ROI filter to the
+  // \doxygen{otb}{VectorDataToImageFilter}.
+  //
+  // Software Guide : EndLatex
+  
+  // Software Guide : BeginCodeSnippet
+  
+  vectorDataRendering->SetInput(extractROI->GetOutput());
+  vectorDataRendering->SetSize(size);
+  vectorDataRendering->SetOrigin(origin);
+  vectorDataRendering->SetSpacing(spacing);
+  
+  // Software Guide : EndCodeSnippet
+
+  // Software Guide : BeginLatex
+  //
+  // Since we are interested in binary rendering, we need to set the
+  // appropriate rendering style.
+  //
+  // Software Guide : EndLatex
+  
+  // Software Guide : BeginCodeSnippet
+
+  vectorDataRendering->SetRenderingStyleType(VectorDataToImageFilterType::Binary);
+
+  // Software Guide : EndCodeSnippet
+  
+  // Software Guide : BeginLatex
+  //
+  // The rendering filter will return a binary image with label 0 when
+  // outside the rasterized vector features and 255 when inside. To
+  // get a fancier rendering we will substitute a blue color to the
+  // foreground value and green to the background value.
+  //
+  // Software Guide : EndLatex
+
+  // Software Guide : BeginCodeSnippet
+  
+  typedef itk::RGBAPixel<unsigned char> RGBAPixelType;
+  typedef otb::Image<RGBAPixelType,2>   RGBAImageType;
+  typedef itk::ChangeLabelImageFilter<ImageType,
+    RGBAImageType> ChangeLabelImageFilterType;
+  
+  ChangeLabelImageFilterType::Pointer 
+    changeLabelFilter = ChangeLabelImageFilterType::New();
+  
+  RGBAPixelType green, blue;
+  green.SetAlpha(255);
+  green.SetGreen(255);
+  blue.SetAlpha(255);
+  blue.SetBlue(255);
+  
+  changeLabelFilter->SetChange(0,blue);
+  changeLabelFilter->SetChange(255,green);
+  changeLabelFilter->SetInput(vectorDataRendering->GetOutput());
+  
+  // Software Guide : EndCodeSnippet
+
+  // Software Guide : BeginLatex
+  //
+  // Last step is to write the image to the disk using a
+  // \doxygen{otb}{ImageFileWriter}.
+  //
+  // Software Guide : EndLatex
+
+  // Software Guide : BeginCodeSnippet
+  
+  typedef otb::ImageFileWriter<RGBAImageType> WriterType;
+  WriterType::Pointer writer = WriterType::New();
+  writer->SetInput(changeLabelFilter->GetOutput());
+  writer->SetFileName(argv[2]);
+  writer->Update();
+
+  // Software Guide : EndCodeSnippet
+
+  //  Software Guide : BeginLatex
+  //
+  // \begin{figure}
+  // \center
+  // \includegraphics[width=0.4\textwidth]{ArcachonRasterizedCoastline.eps}
+  // \itkcaption[Rasterized SRTM water bodies near Arcachon, France.]{Rasterized SRTM water bodies near Arcachon, France.}
+  // \label{fig:RasterizationFilterOutput}
+  // \end{figure}
+  //
+  //  Figure \ref{fig:RasterizationFilterOutput} illustrates the use
+  //  of the rasterization filter on SRTM water bodies mask near
+  //  Arcachon in France. Ocean appears in blue while land appears in green.
+  //
+  //  Software Guide : EndLatex
+
+
+  return EXIT_SUCCESS;
+}