Visual Servoing Platform  version 3.0.0
homographyHartleyDLT2DObject.cpp

Example of the HartleyDLT homography estimation algorithm using vpHomography class.

/****************************************************************************
*
* This file is part of the ViSP software.
* Copyright (C) 2005 - 2015 by Inria. All rights reserved.
*
* This software is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* ("GPL") version 2 as published by the Free Software Foundation.
* See the file LICENSE.txt at the root directory of this source
* distribution for additional information about the GNU GPL.
*
* For using ViSP with software that can not be combined with the GNU
* GPL, please contact Inria about acquiring a ViSP Professional
* Edition License.
*
* See http://visp.inria.fr for more information.
*
* This software was developed at:
* Inria Rennes - Bretagne Atlantique
* Campus Universitaire de Beaulieu
* 35042 Rennes Cedex
* France
*
* If you have questions regarding the use of this file, please contact
* Inria at visp@inria.fr
*
* This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
* WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*
* Description:
* Example of the HartleyDLT homography estimation algorithm.
*
* Authors:
* Eric Marchand
*
*****************************************************************************/
#include <visp3/core/vpMath.h>
#include <visp3/core/vpRotationMatrix.h>
#include <visp3/vision/vpHomography.h>
#include <visp3/core/vpDebug.h>
#include <visp3/core/vpThetaUVector.h>
#include <visp3/core/vpPoint.h>
#include <visp3/core/vpMath.h>
#include <visp3/core/vpHomogeneousMatrix.h>
#include <visp3/core/vpDebug.h>
#include <visp3/io/vpParseArgv.h>
#include <stdlib.h>
// List of allowed command line options
#define GETOPTARGS "h"
#define L 0.1
#define nbpt 5
void usage(const char *name, const char *badparam);
bool getOptions(int argc, const char **argv);
void usage(const char *name, const char *badparam)
{
fprintf(stdout, "\n\
Test the HartleyDLT homography estimation algorithm.\n\
\n\
SYNOPSIS\n\
%s [-h]\n", name);
fprintf(stdout, "\n\
OPTIONS: Default\n\
-h\n\
Print the help.\n");
if (badparam) {
fprintf(stderr, "ERROR: \n" );
fprintf(stderr, "\nBad parameter [%s]\n", badparam);
}
}
bool getOptions(int argc, const char **argv)
{
const char *optarg_;
int c;
while ((c = vpParseArgv::parse(argc, argv, GETOPTARGS, &optarg_)) > 1) {
switch (c) {
case 'h': usage(argv[0], NULL); return false; break;
default:
usage(argv[0], optarg_);
return false; break;
}
}
if ((c == 1) || (c == -1)) {
// standalone param or error
usage(argv[0], NULL);
std::cerr << "ERROR: " << std::endl;
std::cerr << " Bad argument " << optarg_ << std::endl << std::endl;
return false;
}
return true;
}
int
main(int argc, const char ** argv)
{
try {
// Read the command line options
if (getOptions(argc, argv) == false) {
exit (-1);
}
vpPoint P[nbpt] ; // Point to be tracked
std::vector<double> xa(nbpt), ya(nbpt), xb(nbpt), yb(nbpt);
vpPoint aP[nbpt] ; // Point to be tracked
vpPoint bP[nbpt] ; // Point to be tracked
P[0].setWorldCoordinates(-L,-L, 0 ) ;
P[1].setWorldCoordinates(2*L,-L, 0 ) ;
P[2].setWorldCoordinates(L,L, 0 ) ;
P[3].setWorldCoordinates(-L,3*L, 0 ) ;
P[4].setWorldCoordinates(0,0, 0 ) ;
/*
P[5].setWorldCoordinates(10,20, 0 ) ;
P[6].setWorldCoordinates(-10,12, 0 ) ;
*/
vpHomogeneousMatrix bMo(0,0,1, 0,0,0) ;
vpHomogeneousMatrix aMb(1,0,0.0,vpMath::rad(10),0,vpMath::rad(40)) ;
vpHomogeneousMatrix aMo =aMb*bMo ;
for(unsigned int i=0 ; i < nbpt ; i++)
{
P[i].project(aMo) ;
aP[i] = P[i] ;
xa[i] = P[i].get_x() ;
ya[i] = P[i].get_y() ;
}
for(unsigned int i=0 ; i < nbpt ; i++)
{
P[i].project(bMo) ;
bP[i] = P[i] ;
xb[i] = P[i].get_x() ;
yb[i] = P[i].get_y() ;
}
std::cout << "-------------------------------" <<std::endl ;
std::cout << "aMb "<<std::endl <<aMb << std::endl ;
std::cout << "-------------------------------" <<std::endl ;
vpHomography::DLT(xb, yb, xa, ya, aHb, true) ;
vpTRACE("aHb computed using the DLT algorithm") ;
aHb /= aHb[2][2] ;
std::cout << std::endl << aHb<< std::endl ;
std::cout << "-------------------------------" <<std::endl ;
vpTRACE("extract R, T and n ") ;
aHb.computeDisplacement(aRb, aTb, n) ;
std::cout << "Rotation: aRb" <<std::endl ;
std::cout << aRb << std::endl ;
std::cout << "Translation: aTb" <<std::endl;
std::cout << (aTb).t() <<std::endl ;
std::cout << "Normal to the plane: n" <<std::endl;
std::cout << (n).t() <<std::endl ;
std::cout << "-------------------------------" <<std::endl ;
vpTRACE("Compare with built homoraphy H = R + t/d ") ;
vpPlane bp(0,0,1,1) ;
vpHomography aHb_built(aMb,bp) ;
vpTRACE( "aHb built from the displacement ") ;
std::cout << std::endl <<aHb_built/aHb_built[2][2] << std::endl ;
aHb_built.computeDisplacement(aRb, aTb, n) ;
std::cout << "Rotation: aRb" <<std::endl ;
std::cout << aRb << std::endl ;
std::cout << "Translation: aTb" <<std::endl;
std::cout << (aTb).t() <<std::endl ;
std::cout << "Normal to the plane: n" <<std::endl;
std::cout << (n).t() <<std::endl ;
std::cout << "-------------------------------" <<std::endl ;
vpTRACE("test if ap = aHb bp") ;
for(unsigned int i=0 ; i < nbpt ; i++)
{
std::cout << "Point "<< i<< std::endl ;
vpPoint p ;
std::cout << "(" ;
std::cout << aP[i].get_x()/aP[i].get_w()<<", "<< aP[i].get_y()/aP[i].get_w() ;
std::cout <<") = (" ;
p = aHb*bP[i] ;
std::cout << p.get_x() /p.get_w()<<", "<< p.get_y()/ p.get_w() <<")"<<std::endl ;
}
return 0;
}
catch(vpException e) {
std::cout << "Catch an exception: " << e << std::endl;
return 1;
}
}