gtsam/gtsam/geometry/SimpleCamera.cpp

50 lines
1.3 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 SimpleCamera.cpp
* @brief A simple camera class with a Cal3_S2 calibration
* @date June 30, 2012
* @author Frank Dellaert
*/
#include <gtsam/geometry/SimpleCamera.h>
#include <gtsam/geometry/Cal3_S2.h>
namespace gtsam {
SimpleCamera simpleCamera(const Matrix34& P) {
// P = [A|a] = s K cRw [I|-T], with s the unknown scale
Matrix3 A = P.topLeftCorner(3, 3);
Vector3 a = P.col(3);
// do RQ decomposition to get s*K and cRw angles
Matrix3 sK;
Vector3 xyz;
boost::tie(sK, xyz) = RQ(A);
// Recover scale factor s and K
double s = sK(2, 2);
Matrix3 K = sK / s;
// Recover cRw itself, and its inverse
Rot3 cRw = Rot3::RzRyRx(xyz);
Rot3 wRc = cRw.inverse();
// Now, recover T from a = - s K cRw T = - A T
Vector3 T = -(A.inverse() * a);
return SimpleCamera(Pose3(wRc, T),
Cal3_S2(K(0, 0), K(1, 1), K(0, 1), K(0, 2), K(1, 2)));
}
}