Lidar-Camera calibration tool

tools/LidarCameraCalibration/G2oSolver.h

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+/*
+Copyright (c) 2010-2026, Mathieu Labbe - IntRoLab - Universite de Sherbrooke
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+    * Redistributions of source code must retain the above copyright
+      notice, this list of conditions and the following disclaimer.
+    * Redistributions in binary form must reproduce the above copyright
+      notice, this list of conditions and the following disclaimer in the
+      documentation and/or other materials provided with the distribution.
+    * Neither the name of the Universite de Sherbrooke nor the
+      names of its contributors may be used to endorse or promote products
+      derived from this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY
+DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+#ifndef LIDARCAMERACALIBRATION_G2OSOLVER_H_
+#define LIDARCAMERACALIBRATION_G2OSOLVER_H_
+
+#include "CorrectionSolver.h"
+#include "PatternSearchSolver.h"
+
+#include <rtabmap/core/Version.h>
+
+#ifdef RTABMAP_G2O
+
+// Least squares with g2o: Levenberg-Marquardt on the distances of the lidar edge points
+// to the images' edges (chamfer matching), weighted by the points' weights.
+//
+// - A redescending robust kernel (Welsch) makes a point far from any image edge count for
+//   nothing, as the score does: many lidar edges have no counterpart in the image
+//   (speckle, surfaces the camera does not see the same way).
+// - Levenberg-Marquardt only follows the local slope, and each point is pulled toward its
+//   nearest image edge, often not its own when far from the solution: from a few degrees
+//   away, it stops in a local minimum. So a coarse pattern search gets close first, then
+//   the kernel's scale goes from wide to narrow (9, 3, then 1 x sigma).
+class G2oSolver : public CorrectionSolver
+{
+public:
+	G2oSolver(double sigma) : sigma_(sigma), coarse_(4) {}
+	const char * name() const override {return "g2o";}
+	void solve(const CalibrationProblem & problem, bool estimateTranslation, double p[6]) const override;
+
+private:
+	template<int D>
+	void solveWith(const CalibrationProblem & problem, const std::vector<int> & solved, double p[6]) const;
+
+	double sigma_;
+	PatternSearchSolver coarse_;  // steps of 2 down to 0.25 deg
+};
+
+#endif
+
+#endif /* LIDARCAMERACALIBRATION_G2OSOLVER_H_ */