gtsam/examples/vSLAMexample/vSLAMexample.cpp

137 lines
4.1 KiB
C++

/**
* @file vSLAMexample.cpp
* @brief An vSLAM example for synthesis sequence
* single camera
* @author Duy-Nguyen
*/
#include <gtsam/CppUnitLite/TestHarness.h>
#include <boost/shared_ptr.hpp>
using namespace boost;
#define GTSAM_MAGIC_KEY
#include <gtsam/nonlinear/NonlinearFactorGraph-inl.h>
#include <gtsam/nonlinear/NonlinearOptimizer-inl.h>
#include <gtsam/inference/graph-inl.h>
#include <gtsam/slam/visualSLAM.h>
#include <gtsam/slam/PriorFactor.h>
#include "landmarkUtils.h"
#include "Feature2D.h"
using namespace std;
using namespace gtsam;
using namespace gtsam::visualSLAM;
using namespace boost;
typedef NonlinearOptimizer<Graph,Values> Optimizer;
/* ************************************************************************* */
#define CALIB_FILE "Data/calib.txt"
#define LANDMARKS_FILE "Data/landmarks.txt"
#define POSEFN_PREFIX "Data/ttpy"
#define POSEFN_SUFFIX ".pose"
#define FEATFN_PREFIX "Data/ttpy"
#define FEATFN_SUFFIX ".feat"
#define NUM_IMAGES 10
const int ImageIds[NUM_IMAGES] = {10,20,30,40,50,60,70,80,90,100};
// Store groundtruth values
map<int, Point3> g_landmarks;
vector<Pose3> g_poses;
/* ************************************************************************* */
/**
* Setup vSLAM graph
* by adding and associating 2D features (measurements) detected in each image
* with their corresponding landmarks.
*/
Graph setupGraph()
{
Graph g;
shared_ptrK sK(new Cal3_S2(readCalibData(CALIB_FILE)));
sK->print("Calibration: ");
SharedGaussian sigma(noiseModel::Isotropic::Sigma(2,5.0f));
for (size_t i= 0; i<NUM_IMAGES; i++)
{
std::vector<Feature2D> features = readFeatures(FEATFN_PREFIX, FEATFN_SUFFIX, ImageIds[i]);
for (size_t j = 0; j<features.size(); j++)
g.addMeasurement(features[j].m_p, sigma, i, features[j].m_id, sK);
}
return g;
}
/* ************************************************************************* */
/**
* Read initial values.
* Note: These are ground-truth values, but we just use them as initial estimates.
*/
Values initializeValues()
{
Values initValues;
// Initialize landmarks 3D positions.
for (map<int, Point3>::iterator lmit = g_landmarks.begin(); lmit != g_landmarks.end(); lmit++)
initValues.insert( lmit->first, lmit->second );
// Initialize camera poses.
for (int i = 0; i<NUM_IMAGES; i++)
initValues.insert(i, g_poses[i]);
return initValues;
}
/* ************************************************************************* */
int main()
{
shared_ptr<Graph> graph(new Graph(setupGraph()));
// Read groundtruth landmarks' positions and poses. These will also be used later as intial estimates.
readLandMarks(LANDMARKS_FILE, g_landmarks);
for (int i = 0; i<NUM_IMAGES; i++)
{
Pose3 pose = readPose(POSEFN_PREFIX, POSEFN_SUFFIX, ImageIds[i]) ;
g_poses.push_back( pose );
}
// Create an initial Values structure using groundtruth as the initial estimates
boost::shared_ptr<Values> initialValues(new Values(initializeValues()));
// Add hard constraint on the first pose, used as fixed prior.
graph->addPoseConstraint(0, g_poses[0]);
// Create an ordering of the variables
shared_ptr<Ordering> ordering(new Ordering);
char name[4];
for (size_t i = 0; i<g_landmarks.size(); i++)
{
sprintf(name, "l%d", i); // "li"
*ordering += name;
}
for (size_t i = 0; i<NUM_IMAGES; i++)
{
sprintf(name, "x%d", i); // "xj"
*ordering += name;
}
// Create an optimizer and check its error
// We expect the initial to be zero because Values is the ground truth
Optimizer::shared_solver solver(new Optimizer::solver(ordering));
Optimizer optimizer(graph, initialValues, solver);
cout << "Initial error: " << optimizer.error() << endl;
optimizer.config()->print("Initial estimates: ");
// Optimize the graph.
Optimizer::verbosityLevel verborsity = Optimizer::ERROR;
Optimizer optimResult = optimizer.levenbergMarquardt(1e-5, 1e-5, verborsity);
optimResult.config()->print("After optimization: ");
}
/* ************************************************************************* */