Stereo assist with rolling shutters

• US 9,854,185 B2
• Filed: 12/09/2016
• Issued: 12/26/2017
• Est. Priority Date: 01/15/2013
• Status: Active Grant

• Current Assignee: MobilEye Vision Technologies Ltd. (Intel Corporation)
• Original Assignee: MobilEye Vision Technologies Ltd. (Intel Corporation)
• Inventors: Stein, Gideon, Belman, Efim
• Primary Examiner(s): SENFI, BEHROOZ M
• Application Number:
  US15/374,748
• Publication Number:
  US 20170126995A1
• Time in Patent Office: 382 Days
• CPC Class Codes: B60R 2300/105 using multiple cameras
• CPC Class Codes: B60R 2300/303 using joined images, e.g. multiple camera images
• CPC Class Codes: B60R 2300/8093 for obstacle warning
• CPC Class Codes: G06V 20/56 exterior to a vehicle by using sensors mounted on the vehicle
• CPC Class Codes: H04N 13/25 using two or more image sensors with different characteristics other than in their location or field of view, e.g. having different resolutions or colour pickup characteristics; using image signals from one sensor to control the characteristics of another sensor
• CPC Class Codes: H04N 13/282 for generating image signals corresponding to three or more geometrical viewpoints, e.g. multi-view systems
• CPC Class Codes: H04N 13/296 Synchronisation thereof; Control thereof
• CPC Class Codes: H04N 23/60 Control of cameras or camera modules
• CPC Class Codes: H04N 23/69 Control of means for changing angle of the field of view, e.g. optical zoom objectives or electronic zooming
• CPC Class Codes: H04N 23/90 Arrangement of cameras or camera modules, e.g. multiple cameras in TV studios or sports stadiums
• CPC Class Codes: H04N 25/531 by controlling rolling shutters in CMOS SSIS
• CPC Class Codes: H04N 5/04 Synchronising for television systems using pulse code modulation H04N7/56

Abstract

An imaging system for a vehicle may include a first image capture device having a first field of view and configured to acquire a first image relative to a scene associated with the vehicle, the first image being acquired as a first series of image scan lines captured using a rolling shutter. The imaging system may also include a second image capture device having a second field of view different from the first field of view and that at least partially overlaps the first field of view, the second image capture device being configured to acquire a second image relative to the scene associated with the vehicle, the second image being acquired as a second series of image scan lines captured using a rolling shutter. As a result of overlap between the first field of view and the second field of view, a first overlap portion of the first image corresponds with a second overlap portion of the second image. The first image capture device has a first scan rate associated with acquisition of the first series of image scan lines that is different from a second scan rate associated with acquisition of the second series of image scan lines, such that the first image capture device acquires the first overlap portion of the first image over a period of time during which the second overlap portion of the second image is acquired.

Claims

1. An imaging system, comprising:

a first image capture device having a first field of view and configured to acquire a first series of image scan lines relative to a scene;

a second image capture device having a second field of view different from the first field of view and that at least partially overlaps the first field of view, the second image capture device being configured to acquire a second series of image scan lines relative to the scene;

wherein the first image capture device has a first scan rate associated with acquisition of the first series of image scan lines that is different from a second scan rate associated with acquisition of the second series of image scan lines, such that the first image capture device acquires a first portion of the first series of image scan lines that overlaps a second portion of the second series of image scan lines over a period of time during which the second portion is acquired.

2. The system of claim 1, wherein the second scan rate is greater than the first scan rate.

3. The system of claim 1, further including an image processing device configured to sample a subset of scan lines from the second image capture device within the second portion.

4. The system of claim 1, wherein:

the first image capture device has a first horizontal blanking period associated with acquisition of the first series of image scan lines;

the second image capture device has a second horizontal blanking period associated with acquisition of the second series of image scan lines;

the second horizontal blanking period is less than the first horizontal blanking period.

5. The system of claim 1, wherein:

the first image capture device has a first vertical blanking period associated with acquisition of the first series of image scan lines;

the second image capture device has a second vertical blanking period associated with acquisition of the second series of image scan lines;

the first vertical blanking period is less than the second vertical blanking period.

6. The system of claim 1, wherein:

the first image capture device has a first total frame time associated with acquisition of the first series of image scan lines;

the second image capture device has a second total frame time associated with acquisition of the second series of image scan lines; and

wherein the first total frame time is equal to the second total frame time.

7. The system of claim 1, wherein the second field of view is narrower than the first field of view.

8. The system of claim 1, wherein at least a center of the second field of view substantially corresponds to at least a center the first field of view.

9. The system of claim 1, wherein the period of time is associated with a ratio between the first scan rate and the second scan rate.

10. The system of claim 1, wherein the ratio of the first field of view to the second field of view ranges between 1.25 to 2.25.

11. The system of claim 1, wherein the system further comprises:

at least one processing device configured to;

perform a periodic check to determine whether the first image capture device and the second image capture device are synchronized.

12. The system of claim 11, wherein the at least one processing device is further configured to perform resynchronization of the first image capture device and the second image capture device if the periodic check indicates that the first image capture device and the second image capture device have fallen out of synch.

13. The system of claim 1, wherein:

the first image capture device has a first pixel delay associated with acquisition of the first series of image scan lines;

the second image capture device has a second pixel delay associated with acquisition of the second series of image scan lines;

the first pixel delay is more than the second pixel delay.

14. The system of claim 1, wherein the second overlap portion of the second image corresponds to an entire area of overlap between the first field of view and the second field of view.

15. The system of claim 1, wherein at least a center of the second field of view falls within a lower half of the first field of view.

16. An imaging system, comprising:

at least one processing device configured to;

receive a first series of image scan lines relative to a scene from a first image capture device having a first field of view;

receive a second series of image scan lines relative to the scene from a second image capture device having a second field of view, wherein the second field of view at least partially overlaps the first field of view; and

correlate at least a first area of a first portion of the first series of image scan lines with a corresponding second area of a second portion of the second series of image scan lines, the first portion overlapping the second portion.

17. The system of claim 16, wherein the second field of view is narrower than the first field of view.

18. The system of claim 16, wherein the first image capture device and the second image capture device have differing focal lengths.

19. A method for synchronizing images, comprising:

acquiring, by a first image capture device having a first field of view, a first series of image scan lines relative to a scene;

acquiring, by a second image capture device having a second field of view, a second series of image scan lines relative to the scene, the second field of view being different from the first field of view and at least partially overlapping the first field of view; and

adjusting a timing control parameter for the first image capture device associated with acquisition of the first series of image scan lines to be different from a corresponding timing control parameter for the second image capture device, such that the first image capture device acquires a first portion of the first series of image scan lines that overlaps a second portion of the second series of image scan lines over a period of time during which the second portion is acquired.

20. The method of claim 19, wherein the timing control parameter is at least one of a scan rate, a horizontal blanking period, a vertical blanking period, or a pixel delay.