gtsam/geometry/CalibratedCamera.cpp

/*
 * CalibratedCamera.cpp
 *
 *  Created on: Aug 17, 2009
 *      Author: dellaert
 */

#include "Point2.h"
#include "CalibratedCamera.h"

namespace gtsam {

	/* ************************************************************************* */
	// Auxiliary functions
	/* ************************************************************************* */

	Point2 project_to_camera(const Point3& P) {
		return Point2(P.x() / P.z(), P.y() / P.z());
	}

	Matrix Dproject_to_camera1(const Point3& P) {
		double d = 1.0 / P.z(), d2 = d * d;
		return Matrix_(2, 3, d, 0.0, -P.x() * d2, 0.0, d, -P.y() * d2);
	}

	Point3 backproject_from_camera(const Point2& p, const double scale) {
		return Point3(p.x() * scale, p.y() * scale, scale);
	}

	/* ************************************************************************* */
	// Methods
	/* ************************************************************************* */

	CalibratedCamera::CalibratedCamera(const Pose3& pose) :
		pose_(pose) {
	}

	CalibratedCamera::CalibratedCamera(const Vector &v) : pose_(expmap<Pose3>(v)) {}

	CalibratedCamera::~CalibratedCamera() {}

	CalibratedCamera CalibratedCamera::level(const Pose2& pose2, double height) {
		double st = sin(pose2.theta()), ct = cos(pose2.theta());
		Point3 x(st, -ct, 0), y(0, 0, -1), z(ct, st, 0);
		Rot3 wRc(x, y, z);
		Point3 t(pose2.x(), pose2.y(), height);
		Pose3 pose3(wRc, t);
		return CalibratedCamera(pose3);
	}

	Point2 CalibratedCamera::project(const Point3 & P) const {
		Point3 cameraPoint = transform_to(pose_, P);
		Point2 intrinsic = project_to_camera(cameraPoint);
		return intrinsic;
	}

	/* ************************************************************************* */
	// measurement functions and derivatives
	/* ************************************************************************* */

	Point2 project(const CalibratedCamera& camera, const Point3& point) {
		return camera.project(point);
	}

	/* ************************************************************************* */
	Matrix Dproject_pose(const CalibratedCamera& camera, const Point3& point) {
		Point3 cameraPoint = transform_to(camera.pose(), point);
		Matrix D_cameraPoint_pose = Dtransform_to1(camera.pose(), point);

		Point2 intrinsic = project_to_camera(cameraPoint);
		Matrix D_intrinsic_cameraPoint = Dproject_to_camera1(cameraPoint);

		Matrix D_intrinsic_pose = D_intrinsic_cameraPoint * D_cameraPoint_pose;
		return D_intrinsic_pose;
	}

	/* ************************************************************************* */
	Matrix Dproject_point(const CalibratedCamera& camera, const Point3& point) {
		Point3 cameraPoint = transform_to(camera.pose(),point);
		Matrix D_cameraPoint_point = Dtransform_to2(camera.pose(),point);

		Point2 intrinsic = project_to_camera(cameraPoint);
		Matrix D_intrinsic_cameraPoint = Dproject_to_camera1(cameraPoint);

		Matrix D_intrinsic_point = D_intrinsic_cameraPoint * D_cameraPoint_point;
		return D_intrinsic_point;
	}

	/* ************************************************************************* */
	Point2 Dproject_pose_point(const CalibratedCamera& camera, const Point3& point,
			Matrix& D_intrinsic_pose, Matrix& D_intrinsic_point) {

		Point3 cameraPoint = transform_to(camera.pose(), point);
		Matrix D_cameraPoint_pose = Dtransform_to1(camera.pose(),point); // 3*6
		Matrix D_cameraPoint_point = Dtransform_to2(camera.pose(),point); // 3*3

		Point2 intrinsic = project_to_camera(cameraPoint);
		Matrix D_intrinsic_cameraPoint = Dproject_to_camera1(cameraPoint);

		D_intrinsic_pose = D_intrinsic_cameraPoint * D_cameraPoint_pose; // 2*6
		D_intrinsic_point = D_intrinsic_cameraPoint * D_cameraPoint_point; // 2*3

		return intrinsic;
	}

/* ************************************************************************* */
}