LoGabbiani.H

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00001 /**
00002    \file  Robots/LoBot/lgmd/gabbiani/LoGabbiani.H
00003    \brief Gabbiani's LGMD model.
00004 */
00005 
00006 // //////////////////////////////////////////////////////////////////// //
00007 // The iLab Neuromorphic Vision C++ Toolkit - Copyright (C) 2000-2005   //
00008 // by the University of Southern California (USC) and the iLab at USC.  //
00009 // See http://iLab.usc.edu for information about this project.          //
00010 // //////////////////////////////////////////////////////////////////// //
00011 // Major portions of the iLab Neuromorphic Vision Toolkit are protected //
00012 // under the U.S. patent ``Computation of Intrinsic Perceptual Saliency //
00013 // in Visual Environments, and Applications'' by Christof Koch and      //
00014 // Laurent Itti, California Institute of Technology, 2001 (patent       //
00015 // pending; application number 09/912,225 filed July 23, 2001; see      //
00016 // http://pair.uspto.gov/cgi-bin/final/home.pl for current status).     //
00017 // //////////////////////////////////////////////////////////////////// //
00018 // This file is part of the iLab Neuromorphic Vision C++ Toolkit.       //
00019 //                                                                      //
00020 // The iLab Neuromorphic Vision C++ Toolkit is free software; you can   //
00021 // redistribute it and/or modify it under the terms of the GNU General  //
00022 // Public License as published by the Free Software Foundation; either  //
00023 // version 2 of the License, or (at your option) any later version.     //
00024 //                                                                      //
00025 // The iLab Neuromorphic Vision C++ Toolkit is distributed in the hope  //
00026 // that it will be useful, but WITHOUT ANY WARRANTY; without even the   //
00027 // implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR      //
00028 // PURPOSE.  See the GNU General Public License for more details.       //
00029 //                                                                      //
00030 // You should have received a copy of the GNU General Public License    //
00031 // along with the iLab Neuromorphic Vision C++ Toolkit; if not, write   //
00032 // to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,   //
00033 // Boston, MA 02111-1307 USA.                                           //
00034 // //////////////////////////////////////////////////////////////////// //
00035 //
00036 // Primary maintainer for this file: mviswana usc edu
00037 // $HeadURL: svn://isvn.usc.edu/software/invt/trunk/saliency/src/Robots/LoBot/lgmd/gabbiani/LoGabbiani.H $
00038 // $Id: LoGabbiani.H 13628 2010-06-28 23:48:02Z mviswana $
00039 //
00040 
00041 #ifndef LOBOT_GABBIANI_LGMD_MODEL_DOT_H
00042 #define LOBOT_GABBIANI_LGMD_MODEL_DOT_H
00043 
00044 //------------------------------ HEADERS --------------------------------
00045 
00046 // lobot headers
00047 #include "Robots/LoBot/lgmd/LocustModel.H"
00048 #include "Robots/LoBot/io/LoInputSource.H"
00049 #include "Robots/LoBot/misc/factory.hh"
00050 #include "Robots/LoBot/misc/singleton.hh"
00051 
00052 // INVT headers
00053 #include "Image/Rectangle.H"
00054 
00055 // Standard C++ headers
00056 #include <string>
00057 
00058 //----------------------------- NAMESPACE -------------------------------
00059 
00060 namespace lobot {
00061 
00062 //------------------------- CLASS DEFINITION ----------------------------
00063 
00064 /**
00065    \class lobot::GabbianiModel
00066    \brief Implementation of Gabbiani's LGMD model.
00067 */
00068 class GabbianiModel : public LocustModel {
00069    // Prevent copy and assignment
00070    GabbianiModel(const GabbianiModel&) ;
00071    GabbianiModel& operator=(const GabbianiModel&) ;
00072 
00073    // Handy type to have around
00074    typedef LocustModel base ;
00075 
00076    // Boilerplate code to make the factory work
00077    friend  class subfactory<GabbianiModel, base, base::InitParams> ;
00078    typedef register_factory<GabbianiModel, base, base::InitParams> my_factory ;
00079    static  my_factory register_me ;
00080 
00081    /// Private constructor because this model is instantiated using a
00082    /// factory and accessed solely through the interface provided by its
00083    /// abstract base class.
00084    GabbianiModel(const base::InitParams&) ;
00085 
00086    /// These methods perform the LGMD computations.
00087    ///@{
00088    void update() ;
00089 public:
00090    static float spike_rate(float tti) ;
00091    ///@}
00092 
00093    /// Destructor
00094 private:
00095    ~GabbianiModel() ;
00096 
00097    // This inner class encapsulates various parameters that can be used
00098    // to tweak different aspects of the LGMD model implemented by the
00099    // GabbianiModel class.
00100    class Params : public singleton<Params> {
00101       // Initialization
00102       Params() ; // private because this is a singleton
00103       friend class singleton<Params> ;
00104 
00105       /// Gabbiani's multiplicative model of the LGMD correlates this
00106       /// neuron's firing rate with the product of a logarithmic and an
00107       /// exponential term with a constant of proportionality thrown in.
00108       float m_C ;
00109 
00110       /// The model uses a pair of parameters, viz., alpha and delta, for
00111       /// some reason. FIXME! WHY DO WE NEED THESE PARAMS? WHAT DO THEY
00112       /// MEAN?
00113       float m_alpha, m_delta ;
00114 
00115       /// According to Gabbiani, et al. the LGMD firing rate is strongly
00116       /// correlated to the ratio of the half-size of the approaching
00117       /// object and its velocity. This ratio is a time
00118       /// (length/velocity). This is the time it takes for the
00119       /// approaching object to cover a distance equal to its own (half)
00120       /// size.
00121       float m_l_over_v ;
00122 
00123       /// To better simulate LGMD spikes generated by actual locusts, we
00124       /// can corrupt the "ideal" spikes generated by the Gabbiani model
00125       /// with some Gaussian noise. This parameter specifies the standard
00126       /// deviation to use for the spike noise.
00127       float m_sigma ;
00128 
00129    public:
00130       // Accessing the various parameters
00131       static float C()        {return instance().m_C ;}
00132       static float alpha()    {return instance().m_alpha ;}
00133       static float delta()    {return instance().m_delta ;}
00134       static float sigma()    {return instance().m_sigma ;}
00135       static float l_over_v() {return instance().m_l_over_v ;}
00136 
00137       // Clean-up
00138       ~Params() ;
00139    } ;
00140 } ;
00141 
00142 //-----------------------------------------------------------------------
00143 
00144 } // end of namespace encapsulating this file's definitions
00145 
00146 #endif
00147 
00148 /* So things look consistent in everyone's emacs... */
00149 /* Local Variables: */
00150 /* indent-tabs-mode: nil */
00151 /* End: */
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