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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.
=========================================================================*/
// Software Guide : BeginCommandLineArgs
// INPUTS: {buildingExtractionIndexed.tif}
// OUTPUTS: {buildingExtractionRGB.png}, {buildingExtractionIndexed_scaled.png}
// Software Guide : EndCommandLineArgs
// Software Guide : BeginLatex
//
// Some algorithms produce an indexed image as output. In such images,
// each pixel is given a value according to the region number it belongs to.
// This value starting at 0 or 1 is usually an integer value.
// Often, such images are produced by segmentation or classification algorithms.
//
// If such regions are easy to manipulate -- it is easier and faster to compare two integers
// than a RGB value -- it is different when it comes to displaying the results.
//
// Here we present a convient way to convert such indexed image to a color image. In
// such conversion, it is important to ensure that neighborhood region, which are
// likely to have consecutive number have easily dicernable colors. This is done
// randomly using a hash function by the \doxygen{itk}{ScalarToRGBPixelFunctor}.
//
// Software Guide : EndLatex
#include "otbImage.h"
#include "otbImageFileReader.h"
#include "otbImageFileWriter.h"
#include "itkUnaryFunctorImageFilter.h"
#include "itkScalarToRGBPixelFunctor.h"
#include "itkRescaleIntensityImageFilter.h"
int main(int argc, char * argv[])
{
if (argc != 4)
{
std::cerr << "Usage: " << argv[0] << " <inputImageFile> ";
std::cerr << " <outputRGBImageFile> <outputScaledImageFile>" << std::endl;
return EXIT_FAILURE;
}
const char * inputFilename = argv[1];
const char * outputRGBFilename = argv[2];
const char * outputScaledFilename = argv[3];
typedef otb::Image<unsigned long, 2> ImageType;
typedef otb::Image<itk::RGBPixel<unsigned char>, 2> RGBImageType;
typedef otb::ImageFileReader<ImageType> ReaderType;
ReaderType::Pointer reader = ReaderType::New();
reader->SetFileName(inputFilename);
// Software Guide : BeginLatex
//
// The \doxygen{itk}{UnaryFunctorImageFilter} is the filter in charge of
// calling the functor we specify to do the work for each pixel. Here it is the
// \doxygen{itk}{ScalarToRGBPixelFunctor}.
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
typedef itk::Functor::ScalarToRGBPixelFunctor<unsigned long>
ColorMapFunctorType;
typedef itk::UnaryFunctorImageFilter<ImageType, RGBImageType,
ColorMapFunctorType> ColorMapFilterType;
ColorMapFilterType::Pointer colormapper = ColorMapFilterType::New();
colormapper->SetInput(reader->GetOutput());
// Software Guide : EndCodeSnippet
typedef otb::ImageFileWriter<RGBImageType> WriterType;
WriterType::Pointer writer = WriterType::New();
writer->SetFileName(outputRGBFilename);
writer->SetInput(colormapper->GetOutput());
writer->Update();
//The following is just to produce the input image for the software guide
typedef otb::Image<unsigned char, 2> OutputImageType;
typedef itk::RescaleIntensityImageFilter<ImageType,
OutputImageType> RescalerType;
RescalerType::Pointer rescaler = RescalerType::New();
rescaler->SetInput(reader->GetOutput());
typedef otb::ImageFileWriter<OutputImageType> UCharWriterType;
UCharWriterType::Pointer writer2 = UCharWriterType::New();
writer2->SetFileName(outputScaledFilename);
writer2->SetInput(rescaler->GetOutput());
writer2->Update();
// Software Guide : BeginLatex
// Figure~\ref{fig:INDEXTORGB_FILTER} shows the result of the conversion
// from an indexed image to a color image.
// \begin{figure}
// \center
// \includegraphics[width=0.44\textwidth]{buildingExtractionIndexed_scaled.eps}
// \includegraphics[width=0.44\textwidth]{buildingExtractionRGB.eps}
// \itkcaption[Scaling images]{The original indexed image (left) and the
// conversion to color image.}
// \label{fig:INDEXTORGB_FILTER}
// \end{figure}
//
// Software Guide : EndLatex
return EXIT_SUCCESS;
}
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