gtsam/gtsam/slam/SmartProjectionRigFactor.h

372 lines
14 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 SmartProjectionRigFactor.h
* @brief Smart factor on poses, assuming camera calibration is fixed.
* Same as SmartProjectionPoseFactor, except:
* - it is templated on CAMERA (i.e., it allows cameras beyond pinhole)
* - it admits a different calibration for each measurement (i.e., it
* can model a multi-camera rig system)
* - it allows multiple observations from the same pose/key (again, to
* model a multi-camera system)
* @author Luca Carlone
* @author Frank Dellaert
*/
#pragma once
#include <gtsam/slam/SmartProjectionFactor.h>
namespace gtsam {
/**
*
* @ingroup slam
*
* If you are using the factor, please cite:
* L. Carlone, Z. Kira, C. Beall, V. Indelman, F. Dellaert, Eliminating
* conditionally independent sets in factor graphs: a unifying perspective based
* on smart factors, Int. Conf. on Robotics and Automation (ICRA), 2014.
*/
/**
* This factor assumes that camera calibration is fixed (but each measurement
* can be taken by a different camera in the rig, hence can have a different
* extrinsic and intrinsic calibration). The factor only constrains poses
* (variable dimension is 6 for each pose). This factor requires that values
* contains the involved poses (Pose3). If all measurements share the same
* calibration (i.e., are from the same camera), use SmartProjectionPoseFactor
* instead! If the calibration should be optimized, as well, use
* SmartProjectionFactor instead!
* @ingroup slam
*/
template <class CAMERA>
class SmartProjectionRigFactor : public SmartProjectionFactor<CAMERA> {
private:
typedef SmartProjectionFactor<CAMERA> Base;
typedef SmartProjectionRigFactor<CAMERA> This;
typedef typename CAMERA::CalibrationType CALIBRATION;
typedef typename CAMERA::Measurement MEASUREMENT;
typedef typename CAMERA::MeasurementVector MEASUREMENTS;
static const int DimPose = 6; ///< Pose3 dimension
static const int ZDim = 2; ///< Measurement dimension
protected:
/// vector of keys (one for each observation) with potentially repeated keys
KeyVector nonUniqueKeys_;
/// cameras in the rig (fixed poses wrt body and intrinsics, for each camera)
std::shared_ptr<typename Base::Cameras> cameraRig_;
/// vector of camera Ids (one for each observation, in the same order),
/// identifying which camera took the measurement
FastVector<size_t> cameraIds_;
public:
EIGEN_MAKE_ALIGNED_OPERATOR_NEW
typedef CAMERA Camera;
typedef CameraSet<CAMERA> Cameras;
/// shorthand for a smart pointer to a factor
typedef std::shared_ptr<This> shared_ptr;
/// Default constructor, only for serialization
SmartProjectionRigFactor() {}
/**
* Constructor
* @param sharedNoiseModel isotropic noise model for the 2D feature
* measurements
* @param cameraRig set of cameras (fixed poses wrt body and intrinsics) in
* the camera rig
* @param params parameters for the smart projection factors
*/
SmartProjectionRigFactor(
const SharedNoiseModel& sharedNoiseModel,
const std::shared_ptr<Cameras>& cameraRig,
const SmartProjectionParams& params = SmartProjectionParams())
: Base(sharedNoiseModel, params), cameraRig_(cameraRig) {
// throw exception if configuration is not supported by this factor
if (Base::params_.degeneracyMode != gtsam::ZERO_ON_DEGENERACY)
throw std::runtime_error(
"SmartProjectionRigFactor: "
"degeneracyMode must be set to ZERO_ON_DEGENERACY");
if (Base::params_.linearizationMode != gtsam::HESSIAN)
throw std::runtime_error(
"SmartProjectionRigFactor: "
"linearizationMode must be set to HESSIAN");
}
/**
* add a new measurement, corresponding to an observation from pose "poseKey"
* and taken from the camera in the rig identified by "cameraId"
* @param measured 2-dimensional location of the projection of a
* single landmark in a single view (the measurement)
* @param poseKey key corresponding to the body pose of the camera taking the
* measurement
* @param cameraId ID of the camera in the rig taking the measurement (default
* 0)
*/
void add(const MEASUREMENT& measured, const Key& poseKey,
const size_t& cameraId = 0) {
// store measurement and key
this->measured_.push_back(measured);
this->nonUniqueKeys_.push_back(poseKey);
// also store keys in the keys_ vector: these keys are assumed to be
// unique, so we avoid duplicates here
if (std::find(this->keys_.begin(), this->keys_.end(), poseKey) ==
this->keys_.end())
this->keys_.push_back(poseKey); // add only unique keys
// store id of the camera taking the measurement
cameraIds_.push_back(cameraId);
}
/**
* Variant of the previous "add" function in which we include multiple
* measurements
* @param measurements vector of the 2m dimensional location of the projection
* of a single landmark in the m views (the measurements)
* @param poseKeys keys corresponding to the body poses of the cameras taking
* the measurements
* @param cameraIds IDs of the cameras in the rig taking each measurement
* (same order as the measurements)
*/
void add(const MEASUREMENTS& measurements, const KeyVector& poseKeys,
const FastVector<size_t>& cameraIds = FastVector<size_t>()) {
if (poseKeys.size() != measurements.size() ||
(poseKeys.size() != cameraIds.size() && cameraIds.size() != 0)) {
throw std::runtime_error(
"SmartProjectionRigFactor: "
"trying to add inconsistent inputs");
}
if (cameraIds.size() == 0 && cameraRig_->size() > 1) {
throw std::runtime_error(
"SmartProjectionRigFactor: "
"camera rig includes multiple camera "
"but add did not input cameraIds");
}
for (size_t i = 0; i < measurements.size(); i++) {
add(measurements[i], poseKeys[i],
cameraIds.size() == 0 ? 0 : cameraIds[i]);
}
}
/// return (for each observation) the (possibly non unique) keys involved in
/// the measurements
const KeyVector& nonUniqueKeys() const { return nonUniqueKeys_; }
/// return the calibration object
const std::shared_ptr<Cameras>& cameraRig() const { return cameraRig_; }
/// return the calibration object
const FastVector<size_t>& cameraIds() const { return cameraIds_; }
/**
* print
* @param s optional string naming the factor
* @param keyFormatter optional formatter useful for printing Symbols
*/
void print(
const std::string& s = "",
const KeyFormatter& keyFormatter = DefaultKeyFormatter) const override {
std::cout << s << "SmartProjectionRigFactor: \n ";
for (size_t i = 0; i < nonUniqueKeys_.size(); i++) {
std::cout << "-- Measurement nr " << i << std::endl;
std::cout << "key: " << keyFormatter(nonUniqueKeys_[i]) << std::endl;
std::cout << "cameraId: " << cameraIds_[i] << std::endl;
(*cameraRig_)[cameraIds_[i]].print("camera in rig:\n");
}
Base::print("", keyFormatter);
}
/// equals
bool equals(const NonlinearFactor& p, double tol = 1e-9) const override {
const This* e = dynamic_cast<const This*>(&p);
return e && Base::equals(p, tol) && nonUniqueKeys_ == e->nonUniqueKeys() &&
cameraRig_->equals(*(e->cameraRig())) &&
std::equal(cameraIds_.begin(), cameraIds_.end(),
e->cameraIds().begin());
}
/**
* Collect all cameras involved in this factor
* @param values Values structure which must contain body poses corresponding
* to keys involved in this factor
* @return vector of cameras
*/
typename Base::Cameras cameras(const Values& values) const override {
typename Base::Cameras cameras;
cameras.reserve(nonUniqueKeys_.size()); // preallocate
for (size_t i = 0; i < nonUniqueKeys_.size(); i++) {
const typename Base::Camera& camera_i = (*cameraRig_)[cameraIds_[i]];
const Pose3 world_P_sensor_i =
values.at<Pose3>(nonUniqueKeys_[i]) // = world_P_body
* camera_i.pose(); // = body_P_cam_i
cameras.emplace_back(world_P_sensor_i,
make_shared<typename CAMERA::CalibrationType>(
camera_i.calibration()));
}
return cameras;
}
/**
* error calculates the error of the factor.
*/
double error(const Values& values) const override {
if (this->active(values)) {
return this->totalReprojectionError(this->cameras(values));
} else { // else of active flag
return 0.0;
}
}
/**
* Compute jacobian F, E and error vector at a given linearization point
* @param values Values structure which must contain camera poses
* corresponding to keys involved in this factor
* @return Return arguments are the camera jacobians Fs (including the
* jacobian with respect to both body poses we interpolate from), the point
* Jacobian E, and the error vector b. Note that the jacobians are computed
* for a given point.
*/
void computeJacobiansWithTriangulatedPoint(typename Base::FBlocks& Fs,
Matrix& E, Vector& b,
const Cameras& cameras) const {
if (!this->result_) {
throw("computeJacobiansWithTriangulatedPoint");
} else { // valid result: compute jacobians
b = -cameras.reprojectionError(*this->result_, this->measured_, Fs, E);
for (size_t i = 0; i < Fs.size(); i++) {
const Pose3& body_P_sensor = (*cameraRig_)[cameraIds_[i]].pose();
const Pose3 world_P_body = cameras[i].pose() * body_P_sensor.inverse();
Eigen::Matrix<double, DimPose, DimPose> H;
world_P_body.compose(body_P_sensor, H);
Fs.at(i) = Fs.at(i) * H;
}
}
}
/// linearize and return a Hessianfactor that is an approximation of error(p)
std::shared_ptr<RegularHessianFactor<DimPose> > createHessianFactor(
const Values& values, const double& lambda = 0.0,
bool diagonalDamping = false) const {
// we may have multiple observation sharing the same keys (e.g., 2 cameras
// measuring from the same body pose), hence the number of unique keys may
// be smaller than nrMeasurements
size_t nrUniqueKeys =
this->keys_
.size(); // note: by construction, keys_ only contains unique keys
Cameras cameras = this->cameras(values);
// Create structures for Hessian Factors
std::vector<size_t> js;
std::vector<Matrix> Gs(nrUniqueKeys * (nrUniqueKeys + 1) / 2);
std::vector<Vector> gs(nrUniqueKeys);
if (this->measured_.size() != cameras.size()) // 1 observation per camera
throw std::runtime_error(
"SmartProjectionRigFactor: "
"measured_.size() inconsistent with input");
// triangulate 3D point at given linearization point
this->triangulateSafe(cameras);
if (!this->result_) { // failed: return "empty/zero" Hessian
if (this->params_.degeneracyMode == ZERO_ON_DEGENERACY) {
for (Matrix& m : Gs) m = Matrix::Zero(DimPose, DimPose);
for (Vector& v : gs) v = Vector::Zero(DimPose);
return std::make_shared<RegularHessianFactor<DimPose> >(this->keys_,
Gs, gs, 0.0);
} else {
throw std::runtime_error(
"SmartProjectionRigFactor: "
"only supported degeneracy mode is ZERO_ON_DEGENERACY");
}
}
// compute Jacobian given triangulated 3D Point
typename Base::FBlocks Fs;
Matrix E;
Vector b;
this->computeJacobiansWithTriangulatedPoint(Fs, E, b, cameras);
// Whiten using noise model
this->noiseModel_->WhitenSystem(E, b);
for (size_t i = 0; i < Fs.size(); i++) {
Fs[i] = this->noiseModel_->Whiten(Fs[i]);
}
const Matrix3 P = Base::Cameras::PointCov(E, lambda, diagonalDamping);
// Build augmented Hessian (with last row/column being the information
// vector) Note: we need to get the augumented hessian wrt the unique keys
// in key_
SymmetricBlockMatrix augmentedHessianUniqueKeys =
Base::Cameras::template SchurComplementAndRearrangeBlocks<3, 6, 6>(
Fs, E, P, b, nonUniqueKeys_, this->keys_);
return std::make_shared<RegularHessianFactor<DimPose> >(
this->keys_, augmentedHessianUniqueKeys);
}
/**
* Linearize to Gaussian Factor (possibly adding a damping factor Lambda for
* LM)
* @param values Values structure which must contain camera poses and
* extrinsic pose for this factor
* @return a Gaussian factor
*/
std::shared_ptr<GaussianFactor> linearizeDamped(
const Values& values, const double& lambda = 0.0) const {
// depending on flag set on construction we may linearize to different
// linear factors
switch (this->params_.linearizationMode) {
case HESSIAN:
return this->createHessianFactor(values, lambda);
default:
throw std::runtime_error(
"SmartProjectionRigFactor: unknown linearization mode");
}
}
/// linearize
std::shared_ptr<GaussianFactor> linearize(
const Values& values) const override {
return this->linearizeDamped(values);
}
private:
#ifdef GTSAM_ENABLE_BOOST_SERIALIZATION ///
/// Serialization function
friend class boost::serialization::access;
template <class ARCHIVE>
void serialize(ARCHIVE& ar, const unsigned int /*version*/) {
ar& BOOST_SERIALIZATION_BASE_OBJECT_NVP(Base);
// ar& BOOST_SERIALIZATION_NVP(nonUniqueKeys_);
// ar& BOOST_SERIALIZATION_NVP(cameraRig_);
// ar& BOOST_SERIALIZATION_NVP(cameraIds_);
}
#endif
};
// end of class declaration
/// traits
template <class CAMERA>
struct traits<SmartProjectionRigFactor<CAMERA> >
: public Testable<SmartProjectionRigFactor<CAMERA> > {};
} // namespace gtsam