DOC: finishing up example for VectorDataExtractROI

Examples/Projections/VectorDataExtractROIExample.cxx

@@ -29,6 +29,9 @@
 // Most of the time, you won't be interested in the whole area and would like
 // to focuss only on the area corresponding to your satellite image.
 //
+// The \doxygen{otb}{VectorDataExtractROI} is able to extract the area corresponding
+// to your satellite image, even if the image is still in sensor geometry (provided
+// the sensor model is supported by OTB). Let's see how we can do that.
 //
 // This example demonstrates the use of the
 // \doxygen{otb}{VectorDataExtractROI}.
@@ -60,7 +63,7 @@ int main( int argc, char* argv[] )
 
   typedef double                                             Type;
   typedef otb::VectorData<>                                  VectorDataType;
-  typedef otb::VectorDataExtractROI< VectorDataType >        FilterType;
+
   typedef otb::VectorDataFileReader<VectorDataType>          VectorDataFileReaderType;
   typedef otb::VectorDataFileWriter<VectorDataType>          VectorDataWriterType;
 
@@ -72,11 +75,28 @@ int main( int argc, char* argv[] )
   imageReader->SetFileName(inImageName);
   imageReader->UpdateOutputInformation();
 
+  // Software Guide : BeginLatex
+  //
+  // After the usual declaration (you can check the source file for the details),
+  // we can declare the \doxygen{otb}{VectorDataExtractROI}:
+  //
+  // Software Guide : EndLatex
 
+  // Software Guide : BeginCodeSnippet
+  typedef otb::VectorDataExtractROI< VectorDataType >        FilterType;
   FilterType::Pointer               filter = FilterType::New();
-  VectorDataFileReaderType::Pointer reader = VectorDataFileReaderType::New();
-  VectorDataWriterType::Pointer     writer = VectorDataWriterType::New();
-
+  // Software Guide : EndCodeSnippet
+
+  // Software Guide : BeginLatex
+  //
+  // Then, we need to specify the region to extract. This region is a bit special as
+  // it contains also information related to its reference system (cartographic projection
+  // or sensor model projection). We retrieve all these information from the image
+  // we gave as an input.
+  //
+  // Software Guide : EndLatex
+
+  // Software Guide : BeginCodeSnippet
   TypedRegion region;
   TypedRegion::SizeType                                     size;
   TypedRegion::IndexType                                    index;
@@ -92,18 +112,34 @@ int main( int argc, char* argv[] )
   region.SetSize(size);
   region.SetOrigin(index);
 
-  otb::ImageMetadataInterface::Pointer imageMetadataInterface = otb::ImageMetadataInterface::New();
-  region.SetRegionProjection(imageMetadataInterface->GetProjectionRef(imageReader->GetOutput()->GetMetaDataDictionary()));
+  otb::ImageMetadataInterface::Pointer imageMetadataInterface
+      = otb::ImageMetadataInterface::New();
+  region.SetRegionProjection(
+            imageMetadataInterface->GetProjectionRef(
+                    imageReader->GetOutput()->GetMetaDataDictionary()));
 
   region.SetKeywordList(imageReader->GetOutput()->GetImageKeywordlist());
 
-  reader->SetFileName(inVectorName);
-
-  filter->SetInput(reader->GetOutput());
   filter->SetRegion(region);
+  // Software Guide : EndCodeSnippet
 
+  VectorDataFileReaderType::Pointer reader = VectorDataFileReaderType::New();
+  VectorDataWriterType::Pointer     writer = VectorDataWriterType::New();
+  reader->SetFileName(inVectorName);
   writer->SetFileName(outVectorName);
+
+
+  // Software Guide : BeginLatex
+  //
+  // And finally, we can plug the filter in the pipeline:
+  //
+  // Software Guide : EndLatex
+
+  // Software Guide : BeginCodeSnippet
+  filter->SetInput(reader->GetOutput());
   writer->SetInput(filter->GetOutput());
+  // Software Guide : EndCodeSnippet
+
   writer->Update();