Apparatus and method for sensing depth in every direction

• US 7,429,996 B2
• Filed: 07/16/2002
• Issued: 09/30/2008
• Est. Priority Date: 07/16/2002
• Status: Expired due to Term

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Bradski, Gary R.
• Primary Examiner(s): WONG, ALLEN C
• Application Number:
  US10/197,347
• Publication Number:
  US 20040051782A1
• Time in Patent Office: 2,268 Days
• Field of Search: 348/36, 348/335, 348/37, 356/5.01
• 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:

a stationary camera including;

an image sensor, and

a range finder associated with the camera, the range finder includes a radiation source to emit the modulated radiation into the field of view of the image sensor such that a portion of the radiation is reflected back to the image sensor from one or more objects within the field of view to provide depth information for objects within a field of view of the image sensor of the stationary camera;

a processor coupled to receive information from the image sensor and the depth information from the range finder, the processor to compute a 360 depth map for a detected object within a region of interest from the stationary camera according to the depth information and to process pictures taken by the image sensor according to the 360 degree depth map to capture a panoramic picture in one shot;

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

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.

2. The imaging system of claim 1, wherein the radiation source emits an infrared radiation.

3. The imaging system of claim 1, 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.

4. The imaging system of claim 1, wherein the predetermined threshold is manually set by a user of the image sensor.

5. The imaging system of claim 1, wherein the predetermined threshold corresponds substantially to a level of ambient light present in the image sensor'"'"'s operating environment.

6. The imaging system of claim 1, wherein the predetermined threshold is automatically determined by the image sensor.

7. The imaging system of claim 1, 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.

8. The imaging system of claim 1, wherein the camera is positioned along an axis passing through a vertex and through a focus of the substantially paraboloid-shaped reflector.

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

10. 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 from a stationary camera, 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 from the stationary camera 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 one or more imager pixels within the detector collected during a start collection time and a stop collection time according to the timer;

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; and

generating a 360 degree depth map of at least one object detected within the region of interest from the stationary camera according to the integrated intensity values of the imager pixels.

11. The method of claim 10, 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.

12. The method of claim 11, 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.

13. The method of claim 11, further comprising:

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

14. The method of claim 11, 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.

15. A computer-readable storage medium encoded with computer executable instructions, 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 from a stationary camera, 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 from the stationary camera 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 one or more imager pixels within the detector collected during a start collection time and a stop collection time according to the timer;

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; and

generating a 360 degree depth map of at least one object detected within the region of interest from the stationary camera according to the integrated intensity values of the imager pixels.

16. The computer-readable storage medium of claim 15, wherein the generating of the 360 degree depth map comprises:

calculating the distance to the 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.

17. The computer-readable storage medium of claim 16, 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.

18. The computer-readable storage medium of claim 16, wherein the method further comprises:

displaying the 360 degree depth map of the detected object on a display device for a user.

19. The computer-readable storage medium of claim 16, 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.