LoVector.H

Go to the documentation of this file.
00001 /**
00002    \file Robots/LoBot/misc/LoVector.H
00003 
00004    \brief Some utility types and functions related to vectors and images
00005    of vectors.
00006 */
00007 
00008 // //////////////////////////////////////////////////////////////////// //
00009 // The iLab Neuromorphic Vision C++ Toolkit - Copyright (C) 2000-2005   //
00010 // by the University of Southern California (USC) and the iLab at USC.  //
00011 // See http://iLab.usc.edu for information about this project.          //
00012 // //////////////////////////////////////////////////////////////////// //
00013 // Major portions of the iLab Neuromorphic Vision Toolkit are protected //
00014 // under the U.S. patent ``Computation of Intrinsic Perceptual Saliency //
00015 // in Visual Environments, and Applications'' by Christof Koch and      //
00016 // Laurent Itti, California Institute of Technology, 2001 (patent       //
00017 // pending; application number 09/912,225 filed July 23, 2001; see      //
00018 // http://pair.uspto.gov/cgi-bin/final/home.pl for current status).     //
00019 // //////////////////////////////////////////////////////////////////// //
00020 // This file is part of the iLab Neuromorphic Vision C++ Toolkit.       //
00021 //                                                                      //
00022 // The iLab Neuromorphic Vision C++ Toolkit is free software; you can   //
00023 // redistribute it and/or modify it under the terms of the GNU General  //
00024 // Public License as published by the Free Software Foundation; either  //
00025 // version 2 of the License, or (at your option) any later version.     //
00026 //                                                                      //
00027 // The iLab Neuromorphic Vision C++ Toolkit is distributed in the hope  //
00028 // that it will be useful, but WITHOUT ANY WARRANTY; without even the   //
00029 // implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR      //
00030 // PURPOSE.  See the GNU General Public License for more details.       //
00031 //                                                                      //
00032 // You should have received a copy of the GNU General Public License    //
00033 // along with the iLab Neuromorphic Vision C++ Toolkit; if not, write   //
00034 // to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,   //
00035 // Boston, MA 02111-1307 USA.                                           //
00036 // //////////////////////////////////////////////////////////////////// //
00037 //
00038 // Primary maintainer for this file: mviswana usc edu
00039 // $HeadURL: svn://isvn.usc.edu/software/invt/trunk/saliency/src/Robots/LoBot/misc/LoVector.H $
00040 // $Id: LoVector.H 13811 2010-08-21 02:00:08Z mviswana $
00041 //
00042 
00043 #ifndef LOBOT_VECTOR_DOT_H
00044 #define LOBOT_VECTOR_DOT_H
00045 
00046 //------------------------------ HEADERS --------------------------------
00047 
00048 // lobot headers
00049 #include "Robots/LoBot/util/LoMath.H"
00050 
00051 // INVT image support
00052 #include "Image/Image.H"
00053 #include "Image/Point2D.H"
00054 
00055 // Standard C headers
00056 #include <math.h>
00057 
00058 //----------------------------- NAMESPACE -------------------------------
00059 
00060 namespace lobot {
00061 
00062 //----------------------------- TYPEDEFS --------------------------------
00063 
00064 /// Some parts of Robolocust rely on the notion of a vector (here, we are
00065 /// talking about the mathematical variety, not the container type).
00066 /// Although vectors and points are quite distinct concepts, we simply
00067 /// piggyback off the INVT Point2D implementation for our vectors.
00068 typedef Point2D<float> Vector ;
00069 
00070 /// Some quick operators for vectors
00071 //@{
00072 inline Vector operator*(float k, const Vector& V)
00073 {
00074    return Vector(k * V.i, k * V.j) ;
00075 }
00076 
00077 inline Vector operator*(const Vector& V, float k)
00078 {
00079    return operator*(k, V) ;
00080 }
00081 
00082 inline Vector operator/(const Vector& V, float k)
00083 {
00084    return is_zero(k) ? Vector() : operator*(1.0f/k, V) ;
00085 }
00086 //@}
00087 
00088 /// Return the radial direction of the supplied vector.
00089 inline float direction(const Vector& v)
00090 {
00091    return atan(v.j, v.i) ;
00092 }
00093 
00094 /// Return the unit vector associated with the given radial direction.
00095 inline Vector unit_vector(float dir)
00096 {
00097    return Vector(cos(dir), sin(dir)) ;
00098 }
00099 
00100 /// Return the magnitude of the supplied vector.
00101 inline float magnitude(const Vector& v)
00102 {
00103    return sqrtf((v.i * v.i) + (v.j * v.j)) ;
00104 }
00105 
00106 /// Normalize the supplied vector and return the result.
00107 inline Vector normalized(const Vector& v)
00108 {
00109    return v/magnitude(v) ;
00110 }
00111 
00112 /// Return the dot product of two 2D vectors.
00113 inline float dot(const Vector& a, const Vector& b)
00114 {
00115    return a.i * b.i + a.j * b.j ;
00116 }
00117 
00118 /// Some parts of Robolocust need the notion of a collection of vectors
00119 /// arranged in a 2D grid, i.e., an image of vectors.
00120 typedef Image<Vector> VectorImage ;
00121 
00122 /// From an image of vectors, extract the vector at pixel location (x,y).
00123 inline const Vector& get_vector(const VectorImage& I, int x, int y)
00124 {
00125    return I.getVal(x, y) ;
00126 }
00127 
00128 //-----------------------------------------------------------------------
00129 
00130 } // end of namespace encapsulating this file's definitions
00131 
00132 #endif
00133 
00134 /* So things look consistent in everyone's emacs... */
00135 /* Local Variables: */
00136 /* indent-tabs-mode: nil */
00137 /* End: */
Generated on Sun May 8 08:41:31 2011 for iLab Neuromorphic Vision Toolkit by  doxygen 1.6.3