gtsam/slam/visualSLAM.h

/* ----------------------------------------------------------------------------

 * 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

 * -------------------------------------------------------------------------- */

/*
 * visualSLAM.h
 *
 *  Created on: Jan 14, 2010
 *      Author: Richard Roberts and Chris Beall
 */

#pragma once

#include <gtsam/geometry/Pose3.h>
#include <gtsam/geometry/Point2.h>
#include <gtsam/geometry/SimpleCamera.h>
#include <gtsam/nonlinear/Key.h>
#include <gtsam/nonlinear/NonlinearFactorGraph.h>
#include <gtsam/nonlinear/TupleValues.h>
#include <gtsam/nonlinear/NonlinearEquality.h>
#include <gtsam/nonlinear/NonlinearOptimizer.h>
#include <gtsam/slam/PriorFactor.h>

namespace gtsam { namespace visualSLAM {

	/**
   * Typedefs that make up the visualSLAM namespace.
   */
  typedef TypedSymbol<Pose3,'x'> PoseKey;
  typedef TypedSymbol<Point3,'l'> PointKey;
  typedef LieValues<PoseKey> PoseValues;
  typedef LieValues<PointKey> PointValues;
  typedef TupleValues2<PoseValues, PointValues> Values;
  typedef boost::shared_ptr<Values> shared_values;

  typedef NonlinearEquality<Values, PoseKey> PoseConstraint;
  typedef NonlinearEquality<Values, PointKey> PointConstraint;
	typedef PriorFactor<Values, PoseKey> PosePrior;



  /**
   * Non-linear factor for a constraint derived from a 2D measurement,
   * i.e. the main building block for visual SLAM.
   */
  template <class Cfg=Values, class LmK=PointKey, class PosK=PoseKey>
  class GenericProjectionFactor : public NonlinearFactor2<Cfg, PosK, LmK>, Testable<GenericProjectionFactor<Cfg, LmK, PosK> > {
  protected:

    // Keep a copy of measurement and calibration for I/O
    Point2 z_;
    boost::shared_ptr<Cal3_S2> K_;

  public:

    // shorthand for base class type
    typedef NonlinearFactor2<Cfg, PosK, LmK> Base;

    // shorthand for a smart pointer to a factor
    typedef boost::shared_ptr<GenericProjectionFactor<Cfg, LmK, PosK> > shared_ptr;

    /**
     * Default constructor
     */
    GenericProjectionFactor() : K_(new Cal3_S2(444, 555, 666, 777, 888)) {}

    /**
     * Constructor
     * @param z is the 2 dimensional location of point in image (the measurement)
     * @param sigma is the standard deviation
     * @param cameraFrameNumber is basically the frame number
     * @param landmarkNumber is the index of the landmark
     * @param K the constant calibration
     */
    GenericProjectionFactor(const Point2& z,
					const SharedGaussian& model, PosK j_pose,
					LmK j_landmark, const shared_ptrK& K) :
						Base(model, j_pose, j_landmark), z_(z), K_(K) {
			}

    /**
     * print
     * @param s optional string naming the factor
     */
    void print(const std::string& s = "ProjectionFactor") const {
        Base::print(s);
        z_.print(s + ".z");
    }

    /**
     * equals
     */
    bool equals(const GenericProjectionFactor<Cfg, LmK, PosK>& p, double tol = 1e-9) const {
        return Base::equals(p, tol) && this->z_.equals(p.z_, tol)
                  && this->K_->equals(*p.K_, tol);
    }

    //    /** h(x) */
    //    Point2 predict(const Pose3& pose, const Point3& point) const {
    //      return SimpleCamera(*K_, pose).project(point);
    //    }

    /** h(x)-z */
    Vector evaluateError(const Pose3& pose, const Point3& point,
        boost::optional<Matrix&> H1, boost::optional<Matrix&> H2) const {
      SimpleCamera camera(*K_, pose);
      Point2 reprojectionError(camera.project(point, H1, H2) - z_);
      return reprojectionError.vector();
    }

  private:
    /** Serialization function */
    friend class boost::serialization::access;
    template<class Archive>
    void serialize(Archive & ar, const unsigned int version) {
      //ar & BOOST_SERIALIZATION_NVP(key1_);
      //ar & BOOST_SERIALIZATION_NVP(key2_);
      ar & BOOST_SERIALIZATION_NVP(z_);
      ar & BOOST_SERIALIZATION_NVP(K_);
    }
  };

  // Typedef for general use
  typedef GenericProjectionFactor<Values, PointKey, PoseKey> ProjectionFactor;

  /**
	 * Non-linear factor graph for vanilla visual SLAM
	 */
	class Graph: public NonlinearFactorGraph<Values> {

	public:

		typedef boost::shared_ptr<Graph> shared_graph;

		/** default constructor is empty graph */
		Graph() {
		}

		/** print out graph */
		void print(const std::string& s = "") const {
			NonlinearFactorGraph<Values>::print(s);
		}

		/** equals */
		bool equals(const Graph& p, double tol = 1e-9) const {
			return NonlinearFactorGraph<Values>::equals(p, tol);
		}

		/**
		 *  Add a measurement
		 *  @param j index of camera
		 *  @param p to which pose to constrain it to
		 */
		void addMeasurement(const Point2& z, const SharedGaussian& model,
				PoseKey i, PointKey j, const shared_ptrK& K) {
			boost::shared_ptr<ProjectionFactor> factor(new ProjectionFactor(z, model, i, j, K));
			push_back(factor);
		}

		/**
		 *  Add a constraint on a pose (for now, *must* be satisfied in any Values)
		 *  @param j index of camera
		 *  @param p to which pose to constrain it to
		 */
		void addPoseConstraint(int j, const Pose3& p = Pose3()) {
			boost::shared_ptr<PoseConstraint> factor(new PoseConstraint(j, p));
			push_back(factor);
		}

		/**
		 *  Add a constraint on a point (for now, *must* be satisfied in any Values)
		 *  @param j index of landmark
		 *  @param p to which point to constrain it to
		 */
		void addPointConstraint(int j, const Point3& p = Point3()) {
			boost::shared_ptr<PointConstraint> factor(new PointConstraint(j, p));
			push_back(factor);
		}

		/**
		 *  Add a prior on a pose
		 *  @param j index of camera
		 *  @param p to which pose to constrain it to
		 *  @param model uncertainty model of this prior
		 */
		void addPosePrior(int j, const Pose3& p = Pose3(), const SharedGaussian& model = noiseModel::Unit::Create(1)) {
			boost::shared_ptr<PosePrior> factor(new PosePrior(j, p, model));
			push_back(factor);
		}


	}; // Graph

	// Optimizer
	typedef NonlinearOptimizer<Graph, Values> Optimizer;

} } // namespaces