DIVERGENCE RATIO DISTANCE MAPPING CAMERA

• US 20100110165A1
• Filed: 03/03/2008
• Published: 05/06/2010
• Est. Priority Date: 03/23/2007
• Status: Active Grant

• Current Assignee: Keigo Iizuka
• Original Assignee: Keigo Iizuka
• Inventors: Iizuka, Keigo
• Granted Patent: US 8,982,191 B2
• Time in Patent Office: Days
• US Class Current: 348/50
• CPC Class Codes: G01S 17/08 for measuring distance only indirect measurement G01S17/46; active triangulation systems G01S17/48
• CPC Class Codes: G01S 17/89 for mapping or imaging
• CPC Class Codes: G06T 2207/10016 Video; Image sequence
• CPC Class Codes: G06T 7/586 from multiple light sources, e.g. photometric stereo
• CPC Class Codes: H04N 13/207 using a single 2D image sensor
• CPC Class Codes: H04N 13/254 in combination with electromagnetic radiation sources for illuminating objects

Abstract

The present invention relates to a method and system for detecting and mapping three-dimensional information pertaining to one or more target objects. More particularly, the invention consists of selecting one or more target objects, illuminating the one or more target objects using a first light source and capturing an image of the one or more target objects, then, illuminating the same one or more target objects using a second light source and capturing an image of the one or more target objects and lastly calculating the distance at the midpoint between the two light sources and the one or more target objects based on the decay of intensities of light over distance by analyzing the ratio of the image intensities on a pixel by pixel basis.

Claims

1. A method of obtaining three-dimensional information for one or more target objects is provided, characterized in that it comprises the steps of:

(a) selecting one or more target objects;

(b) illuminating the one or more target objects using a first light source at a distance X₁ from the one or more target objects, and capturing an image I₁ of the one or more target objects using at least one camera device;

(c) illuminating the one or more target objects using a second light source at a distance X₂ from the one or more target objects, and capturing an image I₂ of the one or more target objects using the at least one camera device; and

(d) calculating the distance X between the first and second light sources, and the one or more target objects, based on the decay of intensities of light sources over distances X₁ and X₂, using the ratio of the image intensities between the images I₁ and I₂.

2. The method for obtaining three-dimensional information for one or more target objects as defined in claim 1, characterized in that the distance X between the two light sources and the one or more target objects is calculated based on the distance between the midpoint of the two light sources and the one or more target objects.

3. The method for obtaining three-dimensional information for one or more target objects as defined in claim 1, characterized in that:

(a) the first image I₁ and the second image I₂ are stored on a known storage medium;

(b) the distance between the one or more objects and the midpoint between the two light sources is calculated by analyzing images I₁ and I₂ on a pixel by pixel basis; and

(c) the calculated pixel distance information is stored using a known coordinate storage medium.

4. The method for obtaining three-dimensional information for one or more target objects as defined in claim 1, characterized in that:

(a) the decay of the light intensity over distance X is 1/xⁿ, where n can be either a positive or negative real number including a non-integer.

5. The method for obtaining three-dimensional information for one or more target objects as defined in claim 1, characterized in that it comprises the further step of illuminating the one or more target objects with additional light sources for reduction of the impact of shadow on the measurement of light intensity.

6. The method for obtaining three-dimensional information of one or more target objects as defined in claim 1, characterized in that it further comprises the steps of:

(a) illuminating the one or more target objects using a third light source at a distance X₃ from the one or more target objects and capturing an image I₃ of the one or more target objects;

(b) illuminating the one or more target objects using a fourth light source at a distance X₄ from the one or more target objects and capturing an image I₄ of the one or more target objects;

(c) calculating the set of distances X′

2 between the third and fourth light sources and the one or more target objects based on the decay of intensities of light sources over distances X₃ and X₄ using the ratio of the image intensities between the images I₃ and I₄ on a pixel by pixel basis; and

(d) merging the set of distances developed by the set of distances X′

1 between the first and second light sources with the set of distances developed by the second set of distances X′

2, thereby minimizing the effect of light source shadowing.

7. A system for obtaining three-dimensional information for one or more target objects characterized in that it comprises:

(a) at least two light sources, including a first light source at a distance X₁ from one or more target objects, and a second light source at a distance X₂ from the one or more target objects; and

(b) at least one camera device linked to, or incorporating, at least one computer device, the camera device, or the camera device and computer device together, being operable to;

(i) capture and store digital frame information, including capturing an image I₁ of the one or more target objects, illuminated by the first light source, and an image I₂ of the same one or more target objects, illuminated by the second light source; and

(ii) calculate the distance X between the at least two light sources and the one or more target objects based on the ratio of the decay of image intensities of light sources over distances X₁ and X₂ using the ratio of the image intensities between the images I₁ and I₂.

8. The system for obtaining three-dimensional information for one or more target objects as defined in claim 7, characterized in that the light sources are of the same type.

9. The system for obtaining three-dimensional information for one or more target objects as defined in claim 7, characterized in that to minimize the effect of light source shadowing the system further comprises:

(a) an additional set of light sources of the same type.

10. The system for obtaining three-dimensional information for one or more target objects as defined in claim 7, characterized in that the distance X between the first and second two light sources and the one or more target objects is calculated based on the distance between the one or more target objects and the midpoint of the first and second light sources.

11. The system for obtaining three-dimensional information for one or more target objects as defined in claim 7, characterized in that the system is linked to a storage medium, and characterized in that the computer device is operable to:

(a) store the first image I₁ and the second image I₂ to the storage medium;

(b) calculate the distance between the one or more target objects and the two light sources by analyzing images and I₂ on a pixel by pixel basis; and

(c) store the calculated pixel distance information to the storage medium.

12. The system for obtaining three-dimensional information for one or more target objects as defined in claim 11, characterized in that the system is operable to generate a distance map for the one or more target objects based on the calculated pixel distance information.

13. The system for obtaining three-dimensional information for one or more target objects as defined in claim 7, characterized in that the camera device is, or the camera device and computer device together are, operable to:

(a) capture an image I₃ of the one or more target objects using a third light source at a distance X₃ from the one or more target objects;

(b) capture an image I₄ of the one or more target objects using a fourth light source at a distance X₄ from the one or more target objects and capturing;

(c) calculate a set of distances X′

2 between the third and fourth light sources and the one or more target object based on the decay of intensities of light sources over distances X₃ and X₄ using the ratio of the image intensities between the images I₃ and I₄ on a pixel by pixel basis; and

(d) merge the set of distances X′

1 between the first and second light sources with the set of distances developed by the set of distances X′

2, thereby minimizing the effect of light source shadowing.

14. The system for obtaining three-dimensional information for one or more target objects as defined in claim 7, characterized in that the camera device is linked to at least one video microcontroller for controlling the light sources.

15. The system for obtaining three-dimensional information for one or more target objects as defined in claim 7, characterized in that the video microcontroller is linked to the light sources, and is operable to signal the first light source and the second light source to illuminate the one or more target objects in a sequential manner.

16. The system for obtaining three-dimensional information for one or more target objects as defined in claim 14, characterized in that the video microcontroller and the camera device are linked to enable the camera device to capture the images of the one or more target objects sequentially, while illuminated by the first and second light sources in sequence.

17. The system for obtaining three-dimensional information of one or more target objects as defined in claim 7, characterized in that the system is adapted to calculate distance by replacing the two light sources with two sound transducers.

18. The system for obtaining three-dimensional information of one or more target objects as defined in claim 7, characterized in that the system is integrated with an automobile distance mapping system or accident prevention system.

19. The system for obtaining three-dimensional information of one or more target objects as defined in claim 7, characterized in that the system is integrated with a robot to provide distance mapping information to the robot in relation to one or more target objects.

20. The system for obtaining three-dimensional information of one or more target objects as defined in claim 7, characterized in that the system is integrated with a traffic surveillance system and is operable to obtain three-dimensional information associated with automobiles, such three-dimensional information providing a basis for establishing make and model information for automobiles.

21. The system for obtaining three-dimensional information of one or more target objects as defined in claim 7, characterized in that the system is integrated with a distance mapping system that is operable to provide distance information relative to one or more target objects to an individual with a visual impairment regarding their physical environment.

22. The system for obtaining three-dimensional information of one or more target objects as defined in claim 7, characterized in that the system is integrated with a television studio system to provide three-dimensional information that enables editing of one or more target objects in a three-dimensional studio environment.

23. The system for obtaining three-dimensional information of one or more target objects as defined in claim 7, characterized in that the system is integrated with a biometric authentication system to enable bio-authentication of individuals based on touch-less capture of bio-authentication information such as fingerprints.

24. The system for obtaining three-dimensional information of one or more target objects as defined in claim 7, characterized in that the system is moveable to an arbitrary location.