From 81bf0fb73a79c2e13e882b2ad48453955837d2c1 Mon Sep 17 00:00:00 2001
From: Manuel Grizonnet <manuel.grizonnet@gmail.com>
Date: Thu, 30 Sep 2010 18:06:22 +0200
Subject: [PATCH] ENH:add example for the BandMathFilter in the SG (in
progress)
---
.../BasicFilters/BandMathFilterExample.cxx | 219 ++++++++++++++++++
Examples/BasicFilters/CMakeLists.txt | 3 +
2 files changed, 222 insertions(+)
create mode 100755 Examples/BasicFilters/BandMathFilterExample.cxx
mode change 100644 => 100755 Examples/BasicFilters/CMakeLists.txt
diff --git a/Examples/BasicFilters/BandMathFilterExample.cxx b/Examples/BasicFilters/BandMathFilterExample.cxx
new file mode 100755
index 0000000000..767ba2d6f3
--- /dev/null
+++ b/Examples/BasicFilters/BandMathFilterExample.cxx
@@ -0,0 +1,219 @@
+/*=========================================================================
+
+ 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: {qb_RoadExtract.tif}
+// OUTPUTS: {RoadExtractBandMath.tif}, {RoadExtractBandMath-pretty.jpg}
+// Software Guide : EndCommandLineArgs
+
+// Software Guide : BeginLatex
+//
+// This example demonstrates the use of the
+// \doxygen{otb}{BandMathImageFilter} class which allows
+// to perform mathematical operation on the input images.
+// This filter is based on the mathematical parser library muParser.
+// The built in functions and operators list is available at:
+// http://muparser.sourceforge.net/mup_features.html#idDef2
+// In order to use this filter, at least one input image is to be
+// set. An associated variable name can be specified or not by using
+// the corresponding SetNthInput method. For the nth input image, if
+// no associated variable name has been spefified, a default variable
+// name is given by concatenating the letter "b" (for band) and the
+// corresponding input index. \\
+// Next step is to set the expression according to the variable
+// names. For example, in the default case with three input images the
+// following expression is valid : "(b1+b2)*b3".
+//
+// Software Guide : EndLatex
+
+#include "itkExceptionObject.h"
+#include <iostream>
+
+#include "otbImage.h"
+#include "otbObjectList.h"
+#include "otbVectorImage.h"
+#include "otbImageFileReader.h"
+#include "otbImageFileWriter.h"
+#include "otbMultiToMonoChannelExtractROI.h"
+#include "itkCastImageFilter.h"
+// Software Guide : BeginLatex
+//
+// We start by including the needed header file.
+// The aim of this example is to compute the NDVI indice
+// from a multispecral image and perform a threshold on this
+// indice.
+//
+// Software Guide : EndLatex
+
+// Software Guide : BeginCodeSnippet
+#include "otbBandMathImageFilter.h"
+// Software Guide : EndCodeSnippet
+
+int main( int argc, char* argv[])
+{
+ if (argc != 4)
+ {
+ std::cerr << "Usage: " << argv[0] << " inputImageFile ";
+ std::cerr << " outputImageFile ";
+ std::cerr << " outputPrettyImageFile" << std::endl;
+ return EXIT_FAILURE;
+ }
+
+// Software Guide : BeginLatex
+//
+// We start by the classical \code{typedef}s needed for reading and
+// writing the images.The \doxygen{otb}{BandMathImageFilter} class
+// works with \doxygen{otb}{Image} as input so we need to define additional
+// filters to extract each layer of the multispectral image
+//
+// Software Guide : EndLatex
+
+// Software Guide : BeginCodeSnippet
+ typedef double PixelType;
+ typedef otb::VectorImage<PixelType, 2> InputImageType;
+ typedef otb::Image<PixelType, 2> OutputImageType;
+ typedef OutputImageType::PixelType VPixelType;
+ typedef otb::MultiToMonoChannelExtractROI<VPixelType, VPixelType> ExtractROIFilterType;
+ typedef otb::ObjectList<ExtractROIFilterType> ExtractROIFilterListType;
+ typedef otb::ImageFileReader<InputImageType> ReaderType;
+ typedef otb::ImageFileWriter<OutputImageType> WriterType;
+// Software Guide : EndCodeSnippet
+
+// Software Guide : BeginLatex
+//
+// We can now define the type for the filter:
+//
+// Software Guide : EndLatex
+
+// Software Guide : BeginCodeSnippet
+ typedef otb::BandMathImageFilter<OutputImageType> FilterType;
+// Software Guide : EndCodeSnippet
+
+// Software Guide : BeginLatex
+//
+// We instantiate the filter, the reader, and the writer:
+//
+// Software Guide : EndLatex
+
+// Software Guide : BeginCodeSnippet
+ ReaderType::Pointer reader = ReaderType::New();
+ WriterType::Pointer writer = WriterType::New();
+
+ FilterType::Pointer filter = FilterType::New();
+
+ writer->SetInput(filter->GetOutput());
+ reader->SetFileName(argv[1]);
+ writer->SetFileName(argv[2]);
+// Software Guide : EndCodeSnippet
+
+ reader->UpdateOutputInformation();
+
+
+// Software Guide : BeginLatex
+//
+// We need now to extract bands from the \doxygen{otb}{VectorImage},
+// it illustrates the use of the \doxygen{otb}{MultiToMonoChannelExtractROI}.
+// Each extracted layer are inputs of the \doxygen{otb}{BandMathImageFilter}:
+//
+// Software Guide : EndLatex
+
+// Software Guide : BeginCodeSnippet
+ unsigned int bandId = 0;
+ ExtractROIFilterListType::Pointer ChannelExtractorList = ExtractROIFilterListType::New();
+
+ for(unsigned int j = 0; j < reader->GetOutput()->GetNumberOfComponentsPerPixel(); ++j)
+ {
+ std::ostringstream tmpParserVarName;
+ tmpParserVarName << "b" << j+1;
+
+ ExtractROIFilterType::Pointer extractROIFilter = ExtractROIFilterType::New();
+ extractROIFilter->SetInput(reader->GetOutput());
+ extractROIFilter->SetChannel(j+1);
+ extractROIFilter->GetOutput()->UpdateOutputInformation();
+ ChannelExtractorList->PushBack(extractROIFilter);
+ filter->SetNthInput(bandId, ChannelExtractorList->Back()->GetOutput(), tmpParserVarName.str());
+ ++bandId;
+ }
+// Software Guide : EndCodeSnippet
+
+
+ filter->SetExpression("sign(ndvi(b3,b4) - 0.4)");
+
+// Software Guide : BeginLatex
+//
+// Now we can define the mathematical expression to perform on the layers (b1, b2,b3,b4).
+// The filter takes advantage of the parsing capabilities of the muParser library and
+// allows to set the expression as on a digital calculator. \\
+// The expression below returns the sign of the ratio $(NIR-RED)/(NIR+RED) - 0,4$.
+// It uses the built-in function sign(x) which return -1 if x<0; 1 if x>0:
+//
+// Software Guide : EndLatex
+
+// Software Guide : BeginCodeSnippet
+ filter->SetExpression("sign((b4-b3)/(b4+b3) - 0.4)");
+// Software Guide : EndCodeSnippet
+
+// Software Guide : BeginLatex
+//
+// The muParser library offers also the possibility to extended existing built-in functions. For example,
+// you can use the OTB expression "ndvi(b3,b4)" with the filter. It will return the same result.
+//
+// Software Guide : EndLatex
+
+// Software Guide : BeginLatex
+//
+// We can now plug the pipeline and run it.
+//
+// Software Guide : EndLatex
+
+// Software Guide : BeginCodeSnippet
+ writer->Update();
+// Software Guide : EndCodeSnippet
+
+// Software Guide : BeginLatex
+//
+// Figure~\ref{fig:BandMathImageFilter} shows the result of the threshold over the NDVI indice
+// to a Quickbird image.
+// \begin{figure}
+// \center
+// \includegraphics[width=0.45\textwidth]{qb_RoadExtract.eps}
+// \includegraphics[width=0.45\textwidth]{RoadExtractBandMath-pretty.eps}
+// \itkcaption[Band Math]{From left to right:
+// Original image, thresholded NDVI indice.}
+// \label{fig:BandMathImageFilter}
+// \end{figure}
+//
+// Software Guide : EndLatex
+
+ typedef otb::Image<unsigned char, 2> OutputPrettyImageType;
+ typedef otb::ImageFileWriter<OutputPrettyImageType> StreamingImageFileWriterType;
+ typedef itk::CastImageFilter<OutputImageType, OutputPrettyImageType> CastImageFilterType;
+
+ StreamingImageFileWriterType::Pointer prettyWriter = StreamingImageFileWriterType::New();
+ CastImageFilterType::Pointer caster = CastImageFilterType::New();
+ caster->SetInput(filter->GetOutput());
+ prettyWriter->SetInput(caster->GetOutput());
+ prettyWriter->SetFileName(argv[3]);
+
+ prettyWriter->Update();
+
+ return EXIT_SUCCESS;
+}
diff --git a/Examples/BasicFilters/CMakeLists.txt b/Examples/BasicFilters/CMakeLists.txt
old mode 100644
new mode 100755
index 38f2469d21..68b1f8e188
--- a/Examples/BasicFilters/CMakeLists.txt
+++ b/Examples/BasicFilters/CMakeLists.txt
@@ -25,6 +25,9 @@ TARGET_LINK_LIBRARIES(MeanShiftVectorImageFilterExample OTBCommon OTBIO OTBBasic
ADD_EXECUTABLE(HillShadingExample HillShadingExample.cxx )
TARGET_LINK_LIBRARIES(HillShadingExample OTBCommon OTBIO OTBBasicFilters)
+ADD_EXECUTABLE(BandMathFilterExample BandMathFilterExample.cxx )
+TARGET_LINK_LIBRARIES(BandMathFilterExample OTBCommon OTBIO OTBBasicFilters)
+
IF( NOT OTB_DISABLE_CXX_TESTING AND BUILD_TESTING )
SET(BASELINE ${OTB_DATA_ROOT}/Baseline/Examples/BasicFilters)
--
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