Color imaging system for locating retroreflectors

• US 20060279745A1
• Filed: 06/13/2005
• Published: 12/14/2006
• Est. Priority Date: 06/13/2005
• Status: Abandoned Application

• Current Assignee: Agilent Technologies, Inc.
• Original Assignee: Agilent Technologies, Inc.
• Inventors: Fouquet, Julie E., Wenstrand, John Stewart
• Application Number:
  US11/151,475
• Publication Number:
  US 20060279745A1
• Time in Patent Office: Days
• US Class Current: 356/614
• CPC Class Codes: G01S 17/46 Indirect determination of position data
• CPC Class Codes: G01S 3/784 using a mosaic of detectors
• CPC Class Codes: G06T 7/73 using feature-based methods

Abstract

An imaging system includes an image sensor, a first light source on-axis with the image sensor, and a controller. The image sensor is configured to generate an image of a field of view including a retroreflector. The first light source is configured to illuminate the retroreflector, and the controller is configured to output the image and location data for the retroreflector.

Claims

1. An imaging system comprising:

an image sensor configured to generate an image of a field of view including a retroreflector;

a first light source on-axis with the image sensor, the first light source configured to illuminate the retroreflector; and

a controller configured to output the image and location data for the retroreflector.

2. The system of claim 1, wherein the controller is configured to determine the location data for the retroreflector based on a difference between a high intensity reflection from the retroreflector of light from the first light source and a low intensity reflection from the retroreflector of ambient light.

3. The system of claim 1, wherein the first light source provides light comprising at least one wavelength, and the retroreflector comprises a filter such that the retroreflector reflects the at least one wavelength.

4. The system of claim 1, wherein the first light source provides light comprising a first infrared light wavelength and a second infrared light wavelength, and wherein the first infrared light is blocked by a retroreflector filter and the second infrared light is reflected by the retroreflector.

5. The system of claim 1, wherein the image sensor comprises a red, green, green, blue (RGGB) light wavelength patterned filter.

6. The system of claim 1, wherein the image sensor comprises a red, green, infrared, blue (RGIB) light wavelength patterned filter.

7. The system of claim 1, wherein the image sensor comprises a red, green, first infrared, green, blue, second infrared (RGI₁/GBI₂) light wavelength patterned filter.

8. The system of claim 1, further comprising:

a second light source off-axis from the image sensor;

wherein the first light source provides light comprising a first wavelength and the second light source provides light comprising a second wavelength.

9. The system of claim 8, wherein the controller is configured to determine the location data for the retroreflector based on a difference between a high intensity reflection from the retroreflector of light from the first light source and a low intensity reflection from the retroreflector of light from the second light source.

10. The system of claim 8, wherein the first wavelength comprises a first visible light wavelength and the second wavelength comprises a second visible light wavelength.

11. The system of claim 10, wherein the first light source comprises a green light source.

12. The system of claim 8, wherein the first wavelength comprises a first infrared light wavelength and the second wavelength comprises a second infrared light wavelength.

13. The system of claim 8, wherein the first wavelength comprises an infrared light wavelength and the second wavelength comprises a visible light wavelength.

14. A retroreflector-tracking system comprising:

a retroreflector configured to reflect light having a first wavelength and block light having a second wavelength;

an image sensor configured to generate an image including a bright retroreflector and an image including a dark retroreflector;

a light source on-axis with the image sensor for providing light at the first wavelegth; and

a controller configured to provide location data for the retroreflector.

15. The system of claim 14, wherein the light source provides illumination at the second wavelength, and wherein the controller is configured to provide the location data based on a difference between the image including the bright retroreflector and the image including the dark retroreflector.

16. A method for generating a color image and the location of a retroreflector, the method comprising:

illuminating a retroreflector with a first light source on-axis with an image sensor;

generating a color image of a field of view of the image sensor including the retroreflector; and

analyzing the color image to determine the location of the retroreflector based on a reflection from the retroreflector.

17. The method of claim 16, wherein analyzing the image comprises determining the location of the retroreflector based on a difference between a high intensity reflection from the retroreflector of light from the first light source and a low intensity reflection from the retroreflector of ambient light.

18. The method of claim 16, further comprising;

illuminating the retroreflector with a second light source off-axis with the image sensor, the first light source providing light having a first wavelength and the second light source providing light having a second wavelength.

19. The method of claim 18, wherein analyzing the image comprises determining the location of the retroreflector based on a difference between a high intensity reflection from the retroreflector of light from the first light source and a low intensity reflection from the retroreflector of light from the second light source.

20. The method of claim 16, wherein illuminating the retroreflector with the first light source comprises illuminating the retroreflector with a first infrared light wavelength and a second infrared light wavelength source, wherein the first infrared light is blocked by a retroreflector filter and the second infrared light is reflected by the retroreflector.