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/*=========================================================================
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.
=========================================================================*/
#include "otbVectorImage.h"
#include "otbImageFileReader.h"
#include "itkImageRegionConstIterator.h"
// Software Guide : BeginLatex
//
// Usually, the streaming process is hidden within the pipeline. This
// allows the user to get rid of the annoying task of splitting the
// images into tiles, and so on. However, for some kinds of
// processing, we do not really need a pipeline: no writer is needed,
// only read access to pixel values is wanted. In these cases, one
// has to explicitly set up the streaming procedure. Fortunately, OTB
// offers a high level of abstraction for this task. We will need to
// include the following header files:
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
#include "otbRAMDrivenAdaptativeStreamingManager.h"
// Software Guide : EndCodeSnippet
int main(int argc, char * argv[])
{
if (argc != 2)
{
std::cerr << "Usage: " << std::endl;
std::cerr << argv[0] << " inputImageFile " << std::endl;
return EXIT_FAILURE;
}
const char * infname = argv[1];
typedef float PixelType;
typedef otb::VectorImage<PixelType, 2> ImageType;
typedef otb::ImageFileReader<ImageType> ImageReaderType;
// Software Guide : BeginLatex
//
// The \doxygen{otb}{RAMDrivenAdaptativeStreamingManager} class manages the streaming
// approaches which are possible with the image type over which it is
// templated. The class \doxygen{itk}{ImageRegionSplitter} is
// templated over the number of dimensions of the image and will
// perform the actual image splitting. More information on splitter can be
// found in section~\ref{sec:Splitters}
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
// typedef otb::StreamingTraits<ImageType> StreamingTraitsType;
// typedef itk::ImageRegionSplitter<2> SplitterType;
typedef otb::RAMDrivenAdaptativeStreamingManager<ImageType> StreamingManagerType;
// Software Guide : EndCodeSnippet
// Software Guide : BeginLatex
//
// Once a region of the image is available, we will use classical
// region iterators to get the pixels.
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
typedef ImageType::RegionType RegionType;
typedef itk::ImageRegionConstIterator<ImageType> IteratorType;
// Software Guide : EndCodeSnippet
// Software Guide : BeginLatex
//
// We instantiate the image file reader, but in order to avoid
// reading the whole image, we call the
// \code{GenerateOutputInformation()} method instead of the
// \code{Update()} one. \code{GenerateOutputInformation()} will make
// available the information about sizes, band, resolutions,
// etc. After that, we can access the largest possible region of the
// input image.
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
ImageReaderType::Pointer reader = ImageReaderType::New();
reader->SetFileName(infname);
reader->GenerateOutputInformation();
RegionType largestRegion = reader->GetOutput()->GetLargestPossibleRegion();
// Software Guide : EndCodeSnippet
// Software Guide : BeginLatex
//
// We set up now the local streaming capabilities by asking the
// streaming traits to compute the number of regions to split the
// image into given the splitter, the user defined number of lines,
// and the input image information.
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
/*
SplitterType::Pointer splitter = SplitterType::New();
unsigned int numberOfStreamDivisions =
StreamingTraitsType::CalculateNumberOfStreamDivisions(
reader->GetOutput(),
largestRegion,
splitter,
otb::SET_BUFFER_NUMBER_OF_LINES,
0, 0, nbLinesForStreaming);
// Software Guide : EndCodeSnippet
std::cout << "The images will be streamed into " <<
numberOfStreamDivisions << " parts." << std::endl;
*/
StreamingManagerType::Pointer
streamingManager = StreamingManagerType::New();
const int availableRAM = 128;
streamingManager->SetAvailableRAMInMB(availableRAM);
streamingManager->PrepareStreaming(reader->GetOutput(), largestRegion);
const unsigned long numberOfStreamDivisions = streamingManager->GetNumberOfSplits();
// Software Guide : BeginLatex
//
// We can now get the split regions and iterate through them.
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
unsigned int piece = 0;
RegionType streamingRegion;
for (piece = 0;
piece < numberOfStreamDivisions;
piece++)
{
// Software Guide : EndCodeSnippet
// Software Guide : BeginLatex
//
// We get the region
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
/*streamingRegion =
splitter->GetSplit(piece, numberOfStreamDivisions, largestRegion);
*/
streamingRegion = streamingManager->GetSplit(piece);
std::cout << "Processing region: " << streamingRegion << std::endl;
// Software Guide : EndCodeSnippet
// Software Guide : BeginLatex
//
// We ask the reader to provide the region.
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
reader->GetOutput()->SetRequestedRegion(streamingRegion);
reader->GetOutput()->PropagateRequestedRegion();
reader->GetOutput()->UpdateOutputData();
// Software Guide : EndCodeSnippet
// Software Guide : BeginLatex
//
// We declare an iterator and walk through the region.
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
IteratorType it(reader->GetOutput(), streamingRegion);
it.GoToBegin();
while (!it.IsAtEnd())
{
std::cout << it.Get() << std::endl;
++it;
}
// Software Guide : EndCodeSnippet
}
return EXIT_SUCCESS;
}
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