ClassifierMAPStrategy.h

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/*  Copyright (C) 2008 National Institute For Space Research (INPE) - Brazil.

    This file is part of the TerraLib - a Framework for building GIS enabled applications.

    TerraLib is free software: you can redistribute it and/or modify
    it under the terms of the GNU Lesser General Public License as published by
    the Free Software Foundation, either version 3 of the License,
    or (at your option) any later version.

    TerraLib is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    GNU Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public License
    along with TerraLib. See COPYING. If not, write to
    TerraLib Team at <terralib-team@terralib.org>.
 */

/*!
  \file terralib/rp/ClassifierMAPStrategy.h
  \brief Maximum a posteriori probability strategy.
 */

#ifndef __TERRALIB_RP_INTERNAL_CLASSIFIERMAPSTRATEGY_H
#define __TERRALIB_RP_INTERNAL_CLASSIFIERMAPSTRATEGY_H

#include "ClassifierStrategy.h"
#include "ClassifierStrategyFactory.h"
#include "../common/progress/TaskProgress.h"
#include "Config.h"

#include <boost/numeric/ublas/matrix.hpp>
#include <boost/shared_ptr.hpp>

#include <map>
#include <vector>

namespace te
{
  namespace rp
  {
    /*!
      \class ClassifierMAPStrategy

      \brief Maximum a posteriori probability strategy.
      
      \ingroup rp_class
     */
    class TERPEXPORT ClassifierMAPStrategy : public ClassifierStrategy
    {
      public:

        /*!
          \class Parameters

          \brief Classifier Parameters
        */
        class TERPEXPORT Parameters : public StrategyParameters
        {
          public:
            
            typedef unsigned int ClassIDT; //!< Class ID type definition (zero means invalid ID).
            
            typedef std::vector< double > ClassSampleT; //!< Class sample type definition.
            
            typedef std::vector< ClassSampleT > ClassSamplesContainerT; //!< Class samples container type definition.
            
            typedef std::map< ClassIDT, ClassSamplesContainerT > MClassesSamplesCT; //!< Multi-classes samples container type definition.

            typedef boost::shared_ptr<MClassesSamplesCT> MClassesSamplesCTPtr; //!< A shared pointer to a multi classes samples container type definition.
            
            MClassesSamplesCTPtr m_trainSamplesPtr; //!< A shared pointer to a always-valid structure where trainning samples are stored.

            std::vector< double > m_prioriProbs; //!< Priori probabilities, one for each class. Values from 0 to 1 (use an empty vector to allow internal calcule of priori probabilities).            
            
            unsigned int m_prioriCalcSampleStep; //!< A positive non-zero sample step used when calculating piori probabilities (default:2 - half of samples will be used);
    
            Parameters();

            ~Parameters();

            //overload
            const Parameters& operator=(const Parameters& params);

            //overload
            void reset() throw( te::rp::Exception );

            //overload
            AbstractParameters* clone() const;
        };

        ClassifierMAPStrategy();

        ~ClassifierMAPStrategy();

        //overload
        bool initialize(StrategyParameters const* const strategyParams) throw(te::rp::Exception);

        //overload
        bool execute(const te::rst::Raster& inputRaster, const std::vector<unsigned int>& inputRasterBands,
                     const std::vector<te::gm::Polygon*>& inputPolygons, te::rst::Raster& outputRaster,
                     const unsigned int outputRasterBand, const bool enableProgressInterface) throw(te::rp::Exception);
                     
      protected :
        
        bool m_isInitialized; //!< Is this instance initialized?
        
        ClassifierMAPStrategy::Parameters m_initParams; //!< Initialization parameters.
        
        std::vector< Parameters::ClassIDT > m_classesIndex2ID; //!< An class index ordered vector of classes IDs;
        
        std::vector< std::vector< double > > m_classesMeans; //!< Classes means;
        
        std::vector< boost::numeric::ublas::matrix< double > > m_classesCovarianceMatrixes; //!< Classes covariance matrixes.
        
        std::vector< boost::numeric::ublas::matrix< double > > m_classesCovarianceInvMatrixes; //!< Classes covariance inverse matrixes.
        
        std::vector< double > m_classesOptizedMAPDiscriminantTerm;  //!< An optimized portion of the MAP discriminant function.
        
        /*!
          \brief Calcule of priori probabilities following the current internal state.
          \param inputRaster Input raster.
          \param inputRasterBands Input raster bands.
          \param progressPtr A pointer to a progress interface, or a null pointer if no progress must be updated.
          \param prioriProbabilities The calculated probabilities.
          \return true if ok, false on errors.
        */
        bool getPrioriProbabilities(
          const te::rst::Raster& inputRaster, 
          const std::vector<unsigned int>& inputRasterBands,
          te::common::TaskProgress * const progressPtr,
          std::vector< double >& prioriProbabilities ) const;        
    };

    /*!
      \class ClassifierMAPStrategyFactory

      \brief Maximum a posteriori probability strategy factory.

      \note Factory key: RegionGrowing
    */
    class TERPEXPORT ClassifierMAPStrategyFactory : public ClassifierStrategyFactory
    {
      public:

        ClassifierMAPStrategyFactory();

        ~ClassifierMAPStrategyFactory();

        //overload
        te::rp::ClassifierStrategy* build();
    };

  } // end namespace rp
}   // end namespace te

#endif // __TERRALIB_RP_INTERNAL_CLASSIFIERMAPSTRATEGY_H