gtsam/geometry/projectiveGeometry.cpp

119 lines
3.6 KiB
C++

/*
* projectiveGeometry.cpp
* @brief Projective geometry, implemented using tensor library
* Created on: Feb 12, 2010
* @author: Frank Dellaert
*/
#include <boost/foreach.hpp>
#include <gtsam/geometry/tensorInterface.h>
#include <gtsam/geometry/projectiveGeometry.h>
namespace gtsam {
using namespace std;
using namespace tensors;
static Eta3 eta;
static Index<3, 'a'> a, _a;
static Index<3, 'b'> b, _b;
static Index<3, 'c'> c, _c;
static Index<3, 'd'> d, _d;
static Index<3, 'd'> e, _e;
static Index<3, 'f'> f, _f;
static Index<3, 'g'> g, _g;
/* ************************************************************************* */
Point2h point2h(double x, double y, double w) {
double data[3];
data[0] = x;
data[1] = y;
data[2] = w;
return data;
}
/* ************************************************************************* */
Line2h line2h(double a, double b, double c) {
double data[3];
data[0] = a;
data[1] = b;
data[2] = c;
return data;
}
/* ************************************************************************* */
Point3h point3h(double X, double Y, double Z, double W) {
double data[4];
data[0] = X;
data[1] = Y;
data[2] = Z;
data[3] = W;
return data;
}
/* ************************************************************************* */
Plane3h plane3h(double a, double b, double c, double d) {
double data[4];
data[0] = a;
data[1] = b;
data[2] = c;
data[3] = d;
return data;
}
/* ************************************************************************* */
Homography2 estimateHomography2(const list<Correspondence>& correspondences) {
// Generate entries of A matrix for linear estimation
Matrix A;
BOOST_FOREACH(const Correspondence& p, correspondences) {
Matrix Ap = reshape(p.first(a) * (eta(_b, _c, _d) * p.second(b)),3,9);
A = stack(2,&A,&Ap);
}
// Call DLT and reshape to Homography
int rank; double error; Vector v;
boost::tie(rank, error, v) = DLT(A);
if (rank < 8) throw invalid_argument("estimateHomography2: not enough data");
return reshape2<3, 3> (v);
}
/* ************************************************************************* */
FundamentalMatrix estimateFundamentalMatrix(const list<Correspondence>& correspondences) {
// Generate entries of A matrix for linear estimation
Matrix A;
BOOST_FOREACH(const Correspondence& p, correspondences) {
Matrix Ap = reshape(p.first(a) * p.second(b),1,9);
A = stack(2,&A,&Ap);
}
// Call DLT and reshape to Homography
int rank; double error; Vector v;
boost::tie(rank, error, v) = DLT(A);
if (rank < 8) throw invalid_argument("estimateFundamentalMatrix: not enough data");
return reshape2<3, 3> (v);
}
/* ************************************************************************* */
TrifocalTensor estimateTrifocalTensor(const list<Triplet>& triplets) {
// Generate entries of A matrix for linear estimation
Matrix A;
BOOST_FOREACH(const Triplet& p, triplets) {
Tensor3<3,3,3> T3 = p.first(a)* (eta(_d,_b,_e) * p.second(d));
Tensor2<3,3> T2 = eta(_f,_c,_g) * p.third(f);
// Take outer product of rank 3 and rank 2, then swap indices 3,4 for reshape
// We get a rank 5 tensor T5(a,_b,_c,_e,_g), where _e and _g index the rows...
Matrix Ap = reshape((T3(a,_b,_e) * T2(_c,_g)).swap34(), 9, 27);
A = stack(2,&A,&Ap);
}
// Call DLT and reshape to Homography
int rank; double error; Vector v;
boost::tie(rank, error, v) = DLT(A);
if (rank < 26) throw invalid_argument("estimateTrifocalTensor: not enough data");
return reshape3<3,3,3>(v);
}
/* ************************************************************************* */
} // namespace gtsam