threshold.hpp

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/*
 * Copyright(c):
 * Signal Image and Communications (SIC) Department 
 * http://www.sic.sp2mi.univ-poitiers.fr/ 
 *  - University of Poitiers, France http://www.univ-poitiers.fr 
 *  - XLIM  Institute UMR CNRS 7252  http://www.xlim.fr/ 
 * 
 * and 
 * 
 * D2 Fluid, Thermic and Combustion 
 *  - University of Poitiers, France http://www.univ-poitiers.fr 
 *  - PPRIME Institute -  UPR CNRS 3346  http://www.pprime.fr
 *  - ISAE-ENSMA http://www.ensma.fr
 *
 * Contributor(s):
 * The SLIP team,
 * Benoit Tremblais <tremblais_AT_sic.univ-poitiers.fr>,
 * Laurent David <laurent.david_AT_lea.univ-poitiers.fr>, 
 * Ludovic Chatellier <ludovic.chatellier_AT_univ-poitiers.fr>, 
 * Lionel Thomas <lionel.thomas_AT_univ-poitiers.fr>, 
 * Denis Arrivault <arrivault_AT_sic.univ-poitiers.fr>, 
 * Julien Dombre <julien.dombre_AT_univ-poitiers.fr>.
 *
 * Description:
 * The Simple Library of Image Processing (SLIP) is a new image processing 
 * library. It is written in the C++ language following as much as possible 
 * the ISO/ANSI C++ standard. It is consequently compatible with any system  
 * satisfying the ANSI C++ complience. It works on different Unix , Linux ,  
 * Mircrosoft Windows and Mac OS X plateforms. SLIP is a research library that  
 * was created by the Signal, Image and Communications (SIC) departement of  
 * the XLIM, UMR 7252 CNRS Institute in collaboration with the Fluids, Thermic  
 * and Combustion departement of the P', UPR 3346 CNRS Institute of the  
 * University of Poitiers.
 * 
 * The SLIP Library source code has been registered to the APP (French Agency 
 * for the Protection of Programs) by the University of Poitiers and CNRS, 
 * under  registration number IDDN.FR.001.300034.000.S.P.2010.000.21000.

 * http://www.sic.sp2mi.univ-poitiers.fr/slip/
 *
 * This software is governed by the CeCILL-C license under French law and
 * abiding by the rules of distribution of free software.  You can  use, 
 * modify and/ or redistribute the software under the terms of the CeCILL-C 
 * license as circulated by CEA, CNRS and INRIA at the following URL 
 * http://www.cecill.info.
 * As a counterpart to the access to the source code and  rights to copy,
 * modify and redistribute granted by the license, users are provided only
 * with a limited warranty  and the software's author,  the holder of the
 * economic rights,  and the successive licensors  have only  limited
 * liability.
 * 
 * In this respect, the user's attention is drawn to the risks associated
 * with loading,  using,  modifying and/or developing or reproducing the
 * software by the user in light of its specific status of free software,
 * that may mean  that it is complicated to manipulate,  and  that  also
 * therefore means  that it is reserved for developers  and  experienced
 * professionals having in-depth computer knowledge. Users are therefore
 * encouraged to load and test the software's suitability as regards their
 * requirements in conditions enabling the security of their systems and/or
 * data to be ensured and,  more generally, to use and operate it in the 
 * same conditions as regards security. 
 *
 * The fact that you are presently reading this means that you have had
 * knowledge of the CeCILL-C license and that you accept its terms.
 */


#ifndef SLIP_THRESHOLD_HPP
#define SLIP_THRESHOLD_HPP

#include <iterator>
#include <algorithm>
#include <numeric>
#include <cassert>
#include <cmath>

namespace slip
{

  template <typename InType, typename  OutType>
  struct binarize_fun
  {
    binarize_fun(const InType& t_value, 
                                 const OutType& false_value,
                                 const OutType& true_value
                                 ):
      t_value_(t_value),false_value_(false_value),true_value_(true_value)
    {}


    OutType operator()(const InType& val)
    {
      return (val <= t_value_) ? false_value_ : true_value_;
    }

    InType t_value_;
    OutType false_value_;
    OutType true_value_;
    
  };

  template <typename InType, typename  OutType>
  struct threshold_fun
  {
    threshold_fun(const InType& t_value, 
                                  const OutType& false_value):
      t_value_(t_value),false_value_(false_value)
    {}
    OutType operator()(const InType& val)
    {
      return (val <= t_value_) ?  false_value_ : OutType(val);
    }

    InType t_value_;
    OutType false_value_;
  };

  template <typename InType, typename  OutType>
  struct db_threshold_fun
  {
    db_threshold_fun(const InType& min_t_value,const InType& max_t_value,
                                     const OutType& false_value):
      min_t_value_(min_t_value),max_t_value_(max_t_value),false_value_(false_value)
    {}
    OutType operator()(const InType& val)
    {
      return ((val >= min_t_value_)&&(val <= max_t_value_)) ?  false_value_ : OutType(val);
    }

    InType min_t_value_;
    InType max_t_value_;
    OutType false_value_;
  };

  template<typename InputIterator, typename OutputIterator>
  inline
  void binarize(InputIterator first,
                                InputIterator last,
                                OutputIterator result,
                                const typename std::iterator_traits<InputIterator>::value_type& t_value,
                                const typename std::iterator_traits<OutputIterator>::value_type& false_value,
                                const typename std::iterator_traits<OutputIterator>::value_type& true_value)     
  {
    assert(first != last);
    
    slip::binarize_fun<
      typename std::iterator_traits<InputIterator>::value_type, 
      typename std::iterator_traits<OutputIterator>::value_type>  
      t_fun(t_value,false_value,true_value);
    
    std::transform(first,last,result,t_fun);
  }

  template<typename InputIterator, typename OutputIterator>
  inline
  void threshold(InputIterator first,
                                 InputIterator last,
                                 OutputIterator result,
                                 const typename std::iterator_traits<InputIterator>::value_type& t_value,
                                 const typename std::iterator_traits<OutputIterator>::value_type& false_value)   
  {
    assert(first != last);
    
    slip::threshold_fun<
      typename std::iterator_traits<InputIterator>::value_type, 
      typename std::iterator_traits<OutputIterator>::value_type>  
      t_fun(t_value,false_value);
    
    std::transform(first,last,result,t_fun);
  }

  template<typename InputIterator, typename OutputIterator>
  inline
  void db_threshold(InputIterator first,
                                    InputIterator last,
                                    OutputIterator result,
                                    const typename std::iterator_traits<InputIterator>::value_type& min_t_value,
                                    const typename std::iterator_traits<InputIterator>::value_type& max_t_value,
                                    const typename std::iterator_traits<OutputIterator>::value_type& false_value)                
  {
    assert(first != last);
    
    slip::db_threshold_fun<
    typename std::iterator_traits<InputIterator>::value_type, 
      typename std::iterator_traits<OutputIterator>::value_type>  
    t_fun(min_t_value,max_t_value,false_value);
  
  std::transform(first,last,result,t_fun);
}


  template<typename InputIterator1,
                   typename RandomAccessIterator1,
                   typename RandomAccessIterator2,
                   typename OutputIterator>
  void multi_threshold(InputIterator1 first, 
                                       InputIterator1 last,
                                       RandomAccessIterator1 first_th, 
                                       RandomAccessIterator1 last_th, 
                                       RandomAccessIterator2 first_level,
                                       RandomAccessIterator2 last_level,
                                       OutputIterator result_first,
                                       OutputIterator result_last)
  {

    assert((last_th-first_th) == (last_level-first_level));
    assert((last - first) == (result_last - result_first));

    RandomAccessIterator1 tmp_t = first_th;
    RandomAccessIterator2 tmp_l = first_level;

    for(;first!=last; ++first, ++result_first)
      { 
                for ( ; first_th != last_th ; ++first_th, ++first_level)
                  {
                    if (*first <= *tmp_t) 
              { 
                *result_first = *tmp_l;
              }
           
                    else if((*(first_th-1) < *first) && (*first <= *first_th))  
              {
                *result_first = *first_level;
              }
                    else if( *first >  *(last_th - 1))
                      {
                                *result_first = *(last_level - 1);
                      }
                  }
                first_th = tmp_t;
                first_level = tmp_l;
      }
  }

 
}//slip::


#endif //SLIP_THRESHOLD_HPP