gtsam/gtsam/slam/tests/testEssentialMatrixFactor.cpp

148 lines
4.6 KiB
C++

/*
* @file testEssentialMatrixFactor.cpp
* @brief Test EssentialMatrixFactor class
* @author Frank Dellaert
* @date December 17, 2013
*/
#include <gtsam/slam/EssentialMatrixFactor.h>
#include <gtsam/slam/dataset.h>
#include <gtsam/nonlinear/NonlinearFactorGraph.h>
#include <gtsam/nonlinear/LevenbergMarquardtOptimizer.h>
#include <gtsam/geometry/CalibratedCamera.h>
#include <gtsam/base/Testable.h>
#include <gtsam/base/numericalDerivative.h>
#include <CppUnitLite/TestHarness.h>
using namespace std;
using namespace gtsam;
const string filename = findExampleDataFile("5pointExample1.txt");
SfM_data data;
bool readOK = readBAL(filename, data);
Rot3 aRb = data.cameras[1].pose().rotation();
Point3 aTb = data.cameras[1].pose().translation();
Point2 pA(size_t i) {
return data.tracks[i].measurements[0].second;
}
Point2 pB(size_t i) {
return data.tracks[i].measurements[1].second;
}
Vector vA(size_t i) {
return EssentialMatrix::Homogeneous(pA(i));
}
Vector vB(size_t i) {
return EssentialMatrix::Homogeneous(pB(i));
}
//*************************************************************************
TEST (EssentialMatrixFactor, testData) {
CHECK(readOK);
// Check E matrix
Matrix expected(3, 3);
expected << 0, 0, 0, 0, 0, -0.1, 0.1, 0, 0;
Matrix aEb_matrix = skewSymmetric(aTb.x(), aTb.y(), aTb.z()) * aRb.matrix();
EXPECT(assert_equal(expected, aEb_matrix,1e-8));
// Check some projections
EXPECT(assert_equal(Point2(0,0),pA(0),1e-8));
EXPECT(assert_equal(Point2(0,0.1),pB(0),1e-8));
EXPECT(assert_equal(Point2(0,-1),pA(4),1e-8));
EXPECT(assert_equal(Point2(-1,0.2),pB(4),1e-8));
// Check homogeneous version
EXPECT(assert_equal((Vector(3) << -1,0.2,1),vB(4),1e-8));
// Check epipolar constraint
for (size_t i = 0; i < 5; i++)
EXPECT_DOUBLES_EQUAL(0, vA(i).transpose() * aEb_matrix * vB(i), 1e-8);
// Check epipolar constraint
EssentialMatrix trueE(aRb, aTb);
for (size_t i = 0; i < 5; i++)
EXPECT_DOUBLES_EQUAL(0, trueE.error(vA(i),vB(i)), 1e-7);
}
//*************************************************************************
TEST (EssentialMatrixFactor, factor) {
EssentialMatrix trueE(aRb, aTb);
noiseModel::Unit::shared_ptr model = noiseModel::Unit::Create(1);
for (size_t i = 0; i < 5; i++) {
EssentialMatrixFactor factor(1, pA(i), pB(i), model);
// Check evaluation
Vector expected(1);
expected << 0;
Matrix HActual;
Vector actual = factor.evaluateError(trueE, HActual);
EXPECT(assert_equal(expected, actual, 1e-7));
// Use numerical derivatives to calculate the expected Jacobian
Matrix HExpected;
HExpected = numericalDerivative11<EssentialMatrix>(
boost::bind(&EssentialMatrixFactor::evaluateError, &factor, _1,
boost::none), trueE);
// Verify the Jacobian is correct
EXPECT(assert_equal(HExpected, HActual, 1e-8));
}
}
//*************************************************************************
TEST (EssentialMatrixFactor, fromConstraints) {
// Here we want to optimize directly on essential matrix constraints
// Yi Ma's algorithm (Ma01ijcv) is a bit cumbersome to implement,
// but GTSAM does the equivalent anyway, provided we give the right
// factors. In this case, the factors are the constraints.
// We start with a factor graph and add constraints to it
// Noise sigma is 1cm, assuming metric measurements
NonlinearFactorGraph graph;
noiseModel::Isotropic::shared_ptr model = noiseModel::Isotropic::Sigma(1,
0.01);
for (size_t i = 0; i < 5; i++)
graph.add(EssentialMatrixFactor(1, pA(i), pB(i), model));
// Check error at ground truth
Values truth;
EssentialMatrix trueE(aRb, aTb);
truth.insert(1, trueE);
EXPECT_DOUBLES_EQUAL(0, graph.error(truth), 1e-8);
// Check error at initial estimate
Values initial;
EssentialMatrix initialE = trueE.retract(
(Vector(5) << 0.1, -0.1, 0.1, 0.1, -0.1));
initial.insert(1, initialE);
EXPECT_DOUBLES_EQUAL(640, graph.error(initial), 1e-2);
// Optimize
LevenbergMarquardtParams parameters;
LevenbergMarquardtOptimizer optimizer(graph, initial, parameters);
Values result = optimizer.optimize();
// Check result
EssentialMatrix actual = result.at<EssentialMatrix>(1);
EXPECT(assert_equal(trueE, actual,1e-1));
// Check error at result
EXPECT_DOUBLES_EQUAL(0, graph.error(result), 1e-4);
// Check errors individually
for (size_t i = 0; i < 5; i++)
EXPECT_DOUBLES_EQUAL(0, actual.error(vA(i),vB(i)), 1e-6);
}
/* ************************************************************************* */
int main() {
TestResult tr;
return TestRegistry::runAllTests(tr);
}
/* ************************************************************************* */