In this paper, we describe a method for finding the pose of an object from a single image. We assume that we can detect and match in the image four or more noncoplanar feature points of the object, and that we know their relative geometry on the object. The method combines two algorithms; the first algorithm,POS (Pose from Orthography and Scaling) approximates the perspective projection with a scaled orthographic projection and finds the rotation matrix and the translation vector of the object by solving a linear system; the second algorithm,POSIT (POS with ITerations), uses in its iteration loop the approximate pose found by POS in order to compute better scaled orthographic projections of the feature points, then applies POS to these projections instead of the original image projections. POSIT converges to accurate pose measurements in a few iterations. POSIT can be used with many feature points at once for added insensitivity to measurement errors and image noise. Compared to classic approaches making use of Newton's method, POSIT does not require starting from an initial guess, and computes the pose using an order of magnitude fewer floating point operations; it may therefore be a useful alternative for real-time operation. When speed is not an issue, POSIT can be written in 25 lines or less in Mathematica; the code is provided in an Appendix.

Model-based object pose in 25 lines of code

Affordable methods and apparatus are disclosed for inputting position, attitude (orientation) or other object characteristic data to computers for the purpose of Computer Aided Design, Painting, Medicine, Teaching, Gaming, Toys, Simulations, Aids to the disabled, and internet or other experiences. Preferred embodiments of the invention utilize electro-optical sensors, and particularly TV Cameras, providing optically inputted data from specialized datum's on objects and/or natural features of objects. Objects can be both static and in motion, from which individual datum positions and movements can be derived, also with respect to other objects both fixed and moving. Real-time photogrammetry is preferably used to determine relationships of portions of one or more datums with respect to a plurality of cameras or a single camera processed by a conventional PC.

Man machine interfaces and applications

Novel man machine interfaces and applications

This invention is a system, a method for tracking the position, and orientation of a probe such as a catheter whose transverse inner dimension may be at most about 2 millimeters. Three planar antennas (26, 28, 30) that at least partly overlap are used to transmit electromagnetic radiation simultaneously, with the radiation transmitted by each antenna (26, 28, 30) having its own spectrum. In the case of single-frequency spectra, the antennas (26, 28, 30) are provided with mechanisms for decoupling them from each other. A receiver (10) inside the probe includes sensors (16a, 16b, 18a, 18b, 20a, 20b) of the three components of the transmitted field, with sensors (16a, 16b, 18a, 18b, 20a, 20b) for at least two of the three components being pairs of sensors (16a, 16b, 18a, 18b, 20a, 20b), such as coils, disposed symmetrically with respect to a common reference point.

Intrabody navigation system for medical applications

A sensing system for monitoring the position and orientation of a rigid object (20). At least 4 point light sources (24) are mounted on the surface of the object (20) in a noncoplanar arrangement. A single electronic camera (26) captures images (59) of the point light sources (24). Locations of the images (59) of the light sources (24) are detected in each video image, and a computer runs a task using these locations to obtain close approximations of the rotation matrix and translation vector (33) of the object (20) in a camera coordinate system (74) at video rate. The object is held by an operator (90) for three-dimensional cursor (94) control and interaction with virtual reality scenes (96) on computer displays (88), and for remote interactive control of teleoperated mechanisms.

Computer vision system for position monitoring in three dimensions using non-coplanar light sources attached to a monitored object

An orthogonally related target point array is provided in fixed relationship to an object. A photo detector image plane obtains images of the target points projected through a lens located a fixed distance from the image plane. Simple algebraic manipulation of image plane position coordinates of the images corresponding to the target points provides for the establishment of a vector replica of the target point array. The vector replica, in turn, is sufficient data to provide spatial information about the object including position and orientation information with full six-degrees-of-freedom.

Method and apparatus for determining location and orientation of objects

An electromagnetic system for determining the orientation including position of a helmet worn by a pilot is disclosed having a transmitting antenna for transmitting electromagnetic field vectors, a receiving antenna for sensing the electromagnetic field vectors generated by the transmitting antenna, and a control apparatus responsive to the sensed electromagnetic field vectors and the transmitted electromagnetic field vectors for determining the compensated orientation of the helmet, the compensated orientation relying upon the rotation matrix determined by a previous solution for the orientation of the helmet.

Helmet metal mass compensation for helmet-mounted sighting system

An electromagnet system for determining the orientation including position of a helmet worn by a pilot is disclosed having a transmitting antenna (11) for transmitting electromagnetic field vectors, a receiving antenna (12) for sensing the electromagnetic field vectors generated by the transmitting antenna, and a control apparatus (22-62) responsive to the sensed electromagnetic field vectors and the transmitted electromagnetic field vectors for determining the compensated orientation of the helmet, the compensated orientation relying upon the rotation matrix determined by a previous solution for the orientation of the helmet.

Jeffrey M. Setterholm

Papers

Method and apparatus for determining location and orientation of objects

Helmet metal mass compensation for helmet-mounted sighting system

Electromagnetic helmet orientation determining system