Apparatus and method for sensing depth in every direction

• US 20040051782A1
• Filed: 07/16/2002
• Published: 03/18/2004
• Est. Priority Date: 07/16/2002
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Bradski, Gary R.
• Granted Patent: US 7,429,996 B2
• Time in Patent Office: Days
• US Class Current: 348/36
• CPC Class Codes: G01S 17/89 for mapping or imaging
• CPC Class Codes: H04N 23/56 provided with illuminating means
• CPC Class Codes: H04N 23/58 Means for changing the camera field of view without moving the camera body, e.g. nutating or panning of optics or image sensors
• CPC Class Codes: H04N 5/2628 Alteration of picture size, shape, position or orientation, e.g. zooming, rotation, rolling, perspective, translation
• CPC Class Codes: H04N 7/18 Closed-circuit television [CCTV] systems, i.e. systems in which the video signal is not broadcast

Abstract

An imaging system configured to take panoramic pictures is disclosed. In one embodiment, the imaging system includes a camera, range finder associated with the camera and configured to provide depth information for objects within a field of view of the camera; and a processor coupled to receive information from the camera and depth information from the range finder, and configured to unwrap pictures taken by the camera according to the depth information.

Claims

1. An imaging system configured to take panoramic pictures, the imaging system comprising:

an image sensor;

a range finder associated with the camera and configured to provide depth information for objects within a field of view of the image sensor; and

a processor coupled to receive information from the image sensor and depth information from the range finder, and configured to unwrap pictures taken by the image sensor according to the depth information.

2. The imaging system of claim 1, wherein the range finder includes a radiation source to emit modulated radiation into the field of view of the image sensor such that a portion of the radiation is reflected back to the imaging system from one or more objects within the field of view;

and

a substantially paraboloid-shaped reflector positioned to orthographically reflect a portion of the reflected radiation to the image sensor with an orthographic lens.

3. The imaging system of claim 2, wherein the radiation source emits an infrared radiation.

4. The imaging system of claim 2, wherein the image sensor further includes;

a filter means positioned to filter out portions of reflected radiation that are not orthographically reflected to the image sensor.

5. The imaging system of claim 2, further including;

a timer connected to the processor and configured to start counting when the radiation is first emitted and configured to stop counting when a first portion of the reflected radiation causes a pixel within the image sensor to exceed a predetermined threshold.

6. The imaging system of claim 5, wherein the predetermined threshold is manually set by a user of the image sensor.

7. The imaging system of claim 5, wherein the predetermined threshold corresponds substantially to a level of ambient light present in the image sensor'"'"'s operating environment.

8. The imaging system of claim 5, wherein the predetermined threshold is automatically determined by the image sensor.

9. The imaging system of claim 5, wherein a stop time measured by the timer is used by the processor to calculate a distance that separates a detected object in the field of view of the imaging system.

10. The imaging system of claim 2, wherein the camera is positioned along an axis passing through a vertex and through a focus of the substantially paraboloid-shaped reflector.

11. The imaging system of claim 1, wherein the image sensor is a range-finding video camera.

12. A method for sensing depth panoramically, the method comprising:

establishing a predetermined intensity threshold for one or more imager pixels within a radiation detector, the imager pixels on an image plane corresponding to a direction of interest in space, the predetermined intensity threshold equal to a predetermined maximum depth to be monitored within the region of interest;

emitting a modulated radiation into the region of interest of space such that a portion of the emitted radiation is reflected back toward a position of the detector from objects positioned within the predetermined maximum depth, and such that a portion of the reflected radiation is further orthographically reflected to the detector from a substantially paraboloid-shaped reflector positioned anterior to the detector with an orthographic lens;

commencing a timer upon an emission of the radiation;

integrating intensity values of the one or more imager pixels; and

stopping the timer after a predetermined time has passed without the predetermined intensity threshold being exceeded, or stopping the timer when an intensity value of one or more of the imager pixels exceeds the predetermined threshold.

14. The method of claim 12, further comprising:

calculating the distance to an object detected within the region of interest as c*R/2, where c is the speed of light and R is the time measured by the timer for an imager pixel in the region of interest to exceed the predetermined threshold.

15. The method of claim 14, further comprising:

establishing a stop integration time equal to

$\frac{\left(\left(1+N\right)*R\right)}{2}$

 

where R is the time measured by the timer for an imager pixel in the region of interest to exceed the predetermined threshold;

emitting a modulated radiation into the region of interest in space;

commencing the timer upon emission of the radiation;

integrating intensity values of one or more imager pixels within the detector; and

stopping the timer and integration of imager pixel values when a time equal to ((1+N)*R) is realized.

16. The method of claim 14, further comprising:

displaying a depth map of the detected object on a display device for a user.

17. The method of claim 14, further comprising:

tracking a moving object, within the region of interest, by periodically adjusting the stop integration time so as to keep one or more imager pixels that correspond to a nearest point of the object at a predetermined intensity value.

18. A method of collision avoidance, the method comprising:

moving a radiation detector at a predetermined rate of speed;

calculating a maximum stopping distance D_stop as T_max=(2*D_stop/C), where T_max equal a maximal integration time and c equals the speed of light; and

establishing a predetermined intensity threshold for one or more imager pixels within the radiation detector, the imager pixels on the image plane corresponding a direction of interest in space, the predetermined intensity threshold equal to predetermined maximal depth to be monitored within the region of interest, emitting a modulated radiation into the region of interest in space, such that a portion of the emitted radiation is reflected back to the detector from objects positioned within the predetermined maximum depth.

19. The method of claim 18, further comprising:

commencing a timer and integration of imager pixel intensity values upon emission of the radiation; and

stopping the integration of imager pixel intensity values when an intensity value of one or more of the imager pixels exceeds the predetermined threshold or when the maximal time is realized.

20. The method of claim 19, further comprising:

receiving a reflected radiation that exceeds the predetermined threshold prior to expiration of T_max; and

altering the speed at least one of distance and direction of travel of the radiation detector.

21. A machine-readable medium having a set of instructions stored, which when executed perform a method comprising:

establishing a predetermined intensity threshold for one or more imager pixels within a radiation detector, the imager pixels on an image plane corresponding to a direction of interest in space, the predetermined intensity threshold equal to a predetermined maximum depth to be monitored within the region of interest;

emitting a modulated radiation into the region of interest of space such that a portion of the emitted radiation is reflected back toward a position of the detector from objects positioned within the predetermined maximum depth, and such that a portion of the reflected radiation is further orthographically reflected to the detector from a substantially paraboloid-shaped reflector positioned anterior to the detector with an orthographic lens;

commencing a timer upon an emission of the radiation;

integrating intensity values of the one or more imager pixels; and

stopping the timer after a predetermined time has passed without the predetermined intensity threshold being exceeded, or stopping the timer when an intensity value of one or more of the imager pixels exceeds the predetermined threshold.

22. The machine-readable medium of claim 21, wherein the method further comprises:

calculating the distance to an object detected within the region of interest as c*R/2, where c is the speed of light and R is the time measured by the timer for an imager pixel in the region of interest to exceed the predetermined threshold.

23. The machine-readable medium of claim 22, wherein the method further comprises:

establishing a stop integration time equal to

$\frac{\left(\left(1+N\right)*R\right)}{2},$

 

where R is the time measured by the timer for an imager pixel in the region of interest to exceed the predetermined threshold;

emitting a modulated radiation into the region of interest in space;

commencing the timer upon emission of the radiation;

integrating intensity values of one or more imager pixels within the detector; and

stopping the timer and integration of imager pixel values when a time equal to ((1+N)*R) is realized.

24. The machine-readable medium of claim 22, wherein the method further comprises:

displaying a depth map of the detected object on a display device for a user.

25. The machine-readable medium of claim 22, wherein the method further comprises

tracking a moving object, within the region of interest, by periodically adjusting the stop integration time so as to keep one or more imager pixels that correspond to a nearest point of the object at a predetermined intensity value.

26. A machine-readable medium having a set of instructions stored, which when executed perform a method comprising:

moving a radiation detector at a predetermined rate of speed;

calculating a maximum stopping distance D_stop as T_max=(2*D_stop/C), where T_max equal a maximal integration time and c equals the speed of light; and

establishing a predetermined intensity threshold for one or more imager pixels within the radiation detector, the imager pixels on the image plane corresponding a direction of interest in space, the predetermined intensity threshold equal to predetermined maximal depth to be monitored within the region of interest, emitting a modulated radiation into the region of interest in space, such that a portion of the emitted radiation is reflected back to the detector from objects positioned within the predetermined maximum depth.

27. The machine-readable medium of claim 26, wherein the method further comprises:

commencing a timer and integration of imager pixel intensity values upon emission of the radiation; and

stopping the integration of imager pixel intensity values when an intensity value of one or more of the imager pixels exceeds the predetermined threshold or when the maximal time is realized.

28. The machine-readable medium of claim 27, wherein the method further comprises:

receiving a reflected radiation that exceeds the predetermined threshold prior to expiration of T_max; and

altering the speed at least one of distance and direction of travel of the radiation detector.