System and method for sensing geometric and photometric attributes of a scene with multiplexed illumination and solid state optical devices

• US 20070268366A1
• Filed: 07/28/2006
• Published: 11/22/2007
• Est. Priority Date: 05/17/2006
• Status: Abandoned Application

• Current Assignee: Mitsubishi Electric Research Laboratories, Inc. (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Electric Research Laboratories, Inc. (Mitsubishi Electric Corporation)
• Inventors: Raskar, Ramesh, Nii, Hideaki
• Application Number:
  US11/495,946
• Publication Number:
  US 20070268366A1
• Time in Patent Office: Days
• US Class Current: 348/143
• CPC Class Codes: G01J 1/42 using electric radiation detectors optical or mechanical part G01J1/04; by comparison with a reference light or electric value G01J1/10
• CPC Class Codes: G01N 2021/557 Detecting specular reflective parts on sample
• CPC Class Codes: G01N 21/55 Specular reflectivity
• CPC Class Codes: G01S 5/16 using electromagnetic waves other than radio waves
• CPC Class Codes: G06T 2207/10016 Video; Image sequence
• CPC Class Codes: G06T 2207/30204 Marker
• CPC Class Codes: G06T 7/73 using feature-based methods
• CPC Class Codes: G06V 10/145 Illumination specially adapted for pattern recognition, e.g. using gratings
• CPC Class Codes: G06V 10/245 by locating a pattern; Special marks for positioning
• CPC Class Codes: H04N 23/20 for generating image signals from infrared radiation only
• CPC Class Codes: H04N 23/56 provided with illuminating means
• CPC Class Codes: H04N 5/222 Studio circuitry; Studio devices; Studio equipment cameras or camera modules comprising electronic image sensors, or control thereof H04N23/00
• CPC Class Codes: H04N 5/33 Transforming infrared radiation cameras or camera modules for generating image signals from infrared radiation H04N23/20; circuitry of SSIS for transforming infrared radiation into image signals H04N25/20

Abstract

An optical emitter and an optical sensor are arranged at locations in a scene. A physical mask is arranged between the emitter and sensor to modulate directional electromagnetic signals from the emitter spatially. The modulated signals are analyzed to determine geometric properties at the location in the scene.

Claims

1. An apparatus for determining geometric properties in a scene, comprising:

means for modulating spatially signals generated by an emitter arranged at a location in a scene, the signals having frequencies in a selected part of an electromagnetic spectrum and a direction;

a set of sensors spatially dispersed in the scene, the set of sensors configured to detect the spatio-modulated signals, and to convert the detected spatio-modulated signals to a corresponding electronic signal; and

means, connected to the set of the sensors, for analyzing values of the electronic signals to determine geometric properties at the location in the scene.

2. The apparatus of claim 1, in which the geometric properties include coordinates of the location.

3. The apparatus of claim 1, in which the geometric properties include an orientation of the emitter at the location.

4. The apparatus of claim 1, in which the geometric properties include a six-dimensional pose of the emitter at the location.

5. The apparatus of claim 1, in which the emitter is moving and in which the geometric properties include a rate of change of coordinates of the location and a rate of change of an orientation of the emitter.

6. The apparatus of claim 1, in which a plurality of the emitters are arranged at a plurality of corresponding locations, and in which the signals of each emitter are multiplexed to determine geometric properties at each location.

7. The apparatus of claim 6, in which the multiplexing is selected from the group consisting of time, wavelength, amplitude, frequency, phase and polarization modulation.

8. The apparatus of claim 1, in which the signals have frequencies that are selected from the group consisting of ultraviolet, visible, near-infrared, far-infrared light, gamma, x-rays, and microwave.

9. The apparatus of claim 1, in which the optical signal is unique at all locations in the scene to generate a space labeling projection.

10. The apparatus of claim 1, further comprising:

a radio frequency identification tag colocated with the emitter.

11. The apparatus of claim 1, in which the emitter is mounted on a moving object.

12. The apparatus of claim 1, further comprising:

means for setting parameters of a camera according to the detected signals.

13. A method for determining geometric properties in a scene, comprising:

modulating spatially signals from an emitter arranged at a location in a scene, the signals having frequencies in a selected part of an electromagnetic spectrum and a direction;

detecting the spatio-modulated signals, and to convert the detected spatio-modulated signals to a corresponding electronic signal; and

analyzing values of the electronic signals to determine geometric properties at the location in the scene.

14. The method of claim 14, in which the geometric properties include coordinates of the location.

15. An apparatus for determining geometric properties in a scene comprising:

an optical emitter configured to emit an optical signal in a scene from a location;

an optical sensor configured to sense the optical signal in the scene;

a passive physical mask arranged between the optical emitter and the optical sensor, the mask configured to modulate spatially the optical signal; and

means for analyzing the spatio-modulated signal to determine geometric properties of the scene at the location.

16. The apparatus of claim 15, in which the optical emitter is a linear array of light emitting diodes in close proximity to the mask, and the optical sensor is a photo diode arranged at the location.

17. The apparatus of claim 15, in which the optical sensor is a linear array of photo diodes in close proximity to the mask, and the optical emitter is a light emitting diode arranged at the location.

18. The apparatus of claim 15, in which the modulating operates at a frequency of about 10,000 Hz or greater.

19. The apparatus of claim 15, in which the spatio-modulation is according to binary patterns.

20. The apparatus of claim 19, in which the binary patterns correspond to Gray codes.

21. The apparatus of claim 20, in which the binary patterns have a one-dimensional symmetry.

22. The apparatus of claim 15, in which the physical mask is symmetrical with respect to epipolar lines associated with the optical signals.

23. The apparatus of claim 15, in which the physical mask is partially transparent to the optical signals and partially opaque to the optical signals.

24. The apparatus of claim 15, in which the physical mask is in a form of a diffraction grating.

25. The apparatus of claim 15, in which the physical mask is adjacent to a lenticular lens.

26. The apparatus of claim 15, in which the physical mask is a moire pattern.

27. An apparatus for determining geometric properties in a scene, comprising:

means for modulating spatially the optical signals from an optical emitter;

a set photo sensors configured to detect the spatio-modulated optical signals, and to convert the spatio-modulated optical signals to a corresponding electronic signal; and

means, connected to the set of the photo sensors, for analyzing values of the electronic signals to determine geometric properties at the location of the optical emitter in the scene.