93 lines
3.3 KiB
C++
93 lines
3.3 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 CameraResectioning.cpp
|
|
* @brief An example of gtsam for solving the camera resectioning problem
|
|
* @author Duy-Nguyen Ta
|
|
* @date Aug 23, 2011
|
|
*/
|
|
|
|
#include <gtsam/inference/Symbol.h>
|
|
#include <gtsam/nonlinear/LevenbergMarquardtOptimizer.h>
|
|
#include <gtsam/geometry/PinholeCamera.h>
|
|
#include <gtsam/geometry/Cal3_S2.h>
|
|
|
|
using namespace gtsam;
|
|
using namespace gtsam::noiseModel;
|
|
using symbol_shorthand::X;
|
|
|
|
/**
|
|
* Unary factor on the unknown pose, resulting from meauring the projection of
|
|
* a known 3D point in the image
|
|
*/
|
|
class ResectioningFactor: public NoiseModelFactorN<Pose3> {
|
|
typedef NoiseModelFactorN<Pose3> Base;
|
|
|
|
Cal3_S2::shared_ptr K_; ///< camera's intrinsic parameters
|
|
Point3 P_; ///< 3D point on the calibration rig
|
|
Point2 p_; ///< 2D measurement of the 3D point
|
|
|
|
public:
|
|
|
|
/// Construct factor given known point P and its projection p
|
|
ResectioningFactor(const SharedNoiseModel& model, const Key& key,
|
|
const Cal3_S2::shared_ptr& calib, const Point2& p, const Point3& P) :
|
|
Base(model, key), K_(calib), P_(P), p_(p) {
|
|
}
|
|
|
|
/// evaluate the error
|
|
Vector evaluateError(const Pose3& pose, OptionalMatrixType H) const override {
|
|
PinholeCamera<Cal3_S2> camera(pose, *K_);
|
|
return camera.project(P_, H, OptionalNone, OptionalNone) - p_;
|
|
}
|
|
};
|
|
|
|
/*******************************************************************************
|
|
* Camera: f = 1, Image: 100x100, center: 50, 50.0
|
|
* Pose (ground truth): (Xw, -Yw, -Zw, [0,0,2.0]')
|
|
* Known landmarks:
|
|
* 3D Points: (10,10,0) (-10,10,0) (-10,-10,0) (10,-10,0)
|
|
* Perfect measurements:
|
|
* 2D Point: (55,45) (45,45) (45,55) (55,55)
|
|
*******************************************************************************/
|
|
int main(int argc, char* argv[]) {
|
|
/* read camera intrinsic parameters */
|
|
Cal3_S2::shared_ptr calib(new Cal3_S2(1, 1, 0, 50, 50));
|
|
|
|
/* 1. create graph */
|
|
NonlinearFactorGraph graph;
|
|
|
|
/* 2. add factors to the graph */
|
|
// add measurement factors
|
|
SharedDiagonal measurementNoise = Diagonal::Sigmas(Vector2(0.5, 0.5));
|
|
std::shared_ptr<ResectioningFactor> factor;
|
|
graph.emplace_shared<ResectioningFactor>(measurementNoise, X(1), calib,
|
|
Point2(55, 45), Point3(10, 10, 0));
|
|
graph.emplace_shared<ResectioningFactor>(measurementNoise, X(1), calib,
|
|
Point2(45, 45), Point3(-10, 10, 0));
|
|
graph.emplace_shared<ResectioningFactor>(measurementNoise, X(1), calib,
|
|
Point2(45, 55), Point3(-10, -10, 0));
|
|
graph.emplace_shared<ResectioningFactor>(measurementNoise, X(1), calib,
|
|
Point2(55, 55), Point3(10, -10, 0));
|
|
|
|
/* 3. Create an initial estimate for the camera pose */
|
|
Values initial;
|
|
initial.insert(X(1),
|
|
Pose3(Rot3(1, 0, 0, 0, -1, 0, 0, 0, -1), Point3(0, 0, 2)));
|
|
|
|
/* 4. Optimize the graph using Levenberg-Marquardt*/
|
|
Values result = LevenbergMarquardtOptimizer(graph, initial).optimize();
|
|
result.print("Final result:\n");
|
|
|
|
return 0;
|
|
}
|