gtsam/gtsam/geometry/StereoCamera.cpp

101 lines
3.2 KiB
C++

/* ----------------------------------------------------------------------------
*GTSAM Copyright 2010, Georgia Tech Research Corporation,
*Atlanta, Georgia 30332-0415
*All Rights Reserved
*Authors: Frank Dellaert, et al. (see THANKS for the full author list)
*See LICENSE for the license information
*-------------------------------------------------------------------------- */
/**
*@file StereoCamera.h
*@brief A Stereo Camera based on two Simple Cameras
*@author Chris Beall
*/
#include <gtsam/geometry/StereoCamera.h>
using namespace std;
using namespace gtsam;
namespace gtsam {
/* ************************************************************************* */
StereoCamera::StereoCamera(const Pose3& leftCamPose,
const Cal3_S2Stereo::shared_ptr K) :
leftCamPose_(leftCamPose), K_(K) {
}
/* ************************************************************************* */
StereoPoint2 StereoCamera::project(const Point3& point,
boost::optional<Matrix&> H1, boost::optional<Matrix&> H2) const {
#ifdef STEREOCAMERA_CHAIN_RULE
const Point3 q = leftCamPose_.transform_to(point, H1, H2);
#else
// omit derivatives
const Point3 q = leftCamPose_.transform_to(point);
#endif
if ( q.z() <= 0 ) throw StereoCheiralityException();
// get calibration
const Cal3_S2Stereo& K = *K_;
const double fx = K.fx(), fy = K.fy(), b = K.baseline();
// calculate scaled but not translated image coordinates
const double d = 1.0 / q.z();
const double x = q.x(), y = q.y();
const double dfx = d*fx, dfy = d*fy;
const double uL = dfx*x;
const double uR = dfx*(x - b);
const double v = dfy*y;
// check if derivatives need to be computed
if (H1 || H2) {
#ifdef STEREOCAMERA_CHAIN_RULE
// just implement chain rule
Matrix D_project_point = Dproject_to_stereo_camera1(q); // 3x3 Jacobian
if (H1) *H1 = D_project_point*(*H1);
if (H2) *H2 = D_project_point*(*H2);
#else
// optimized version, see StereoCamera.nb
if (H1) {
const double v1 = v/fy, v2 = fx*v1, dx=d*x;
*H1 = (Matrix(3, 6) <<
uL*v1, -fx-dx*uL, v2, -dfx, 0.0, d*uL,
uR*v1, -fx-dx*uR, v2, -dfx, 0.0, d*uR,
fy + v*v1, -dx*v , -x*dfy, 0.0, -dfy, d*v
);
}
if (H2) {
const Matrix R(leftCamPose_.rotation().matrix());
*H2 = d * (Matrix(3, 3) <<
fx*R(0, 0) - R(0, 2)*uL, fx*R(1, 0) - R(1, 2)*uL, fx*R(2, 0) - R(2, 2)*uL,
fx*R(0, 0) - R(0, 2)*uR, fx*R(1, 0) - R(1, 2)*uR, fx*R(2, 0) - R(2, 2)*uR,
fy*R(0, 1) - R(0, 2)*v , fy*R(1, 1) - R(1, 2)*v , fy*R(2, 1) - R(2, 2)*v
);
}
#endif
}
// finally translate
return StereoPoint2(K.px() + uL, K.px() + uR, K.py() + v);
}
/* ************************************************************************* */
Matrix StereoCamera::Dproject_to_stereo_camera1(const Point3& P) const {
double d = 1.0 / P.z(), d2 = d*d;
const Cal3_S2Stereo& K = *K_;
double f_x = K.fx(), f_y = K.fy(), b = K.baseline();
return (Matrix(3, 3) <<
f_x*d, 0.0, -d2*f_x* P.x(),
f_x*d, 0.0, -d2*f_x*(P.x() - b),
0.0, f_y*d, -d2*f_y* P.y()
);
}
}