Method and device for multi-camera image correction

• US 9,172,871 B2
• Filed: 12/27/2012
• Issued: 10/27/2015
• Est. Priority Date: 09/29/2010
• Status: Active Grant

• Current Assignee: Huawei Device Company Limited (Huawei Investment & Holding Co., Ltd.)
• Original Assignee: Huawei Device Company Limited (Huawei Investment & Holding Co., Ltd.)
• Inventors: Zhao, Song, Liu, Yuan, Wang, Jing, Zhao, Guangyao
• Primary Examiner(s): ELAHI, SHAN E
• Application Number:
  US13/728,380
• Publication Number:
  US 20130113876A1
• Time in Patent Office: 1,034 Days
• Field of Search: 348/38
• US Class Current: 1/1
• CPC Class Codes: G06T 7/80 Analysis of captured images to determine intrinsic or extrinsic camera parameters, i.e. camera calibration
• CPC Class Codes: H04N 23/698 for achieving an enlarged field of view, e.g. panoramic image capture
• CPC Class Codes: H04N 7/15 Conference systems

Abstract

Embodiments of the present invention provide a method and a device for multi-camera image correction. The method for multi-camera image correction includes: acquiring information of independent images that are captured by each camera and have no overlap area or have an overlap area smaller than a threshold; acquiring, according to information of each independent image, an image correction parameter that corresponds to each camera and allows adjacent independent images to be corrected into a contiguous image; and performing, according to the image correction parameter, correction processing on video data of a camera that corresponds to the image correction parameter. In the embodiments of the present invention, maintenance manpower is saved, adjustment efficiency is improved, and remote maintenance may be performed in the case of no overlap area or of a small overlap area. In addition, images are corrected in a data processing manner, which efficiently ensures precision of image correction.

Claims

1. A method for performing image correction on multiple independent images, the method comprising:

acquiring information of the multiple independent images, wherein each of the multiple independent images is captured by one of multiple cameras and wherein no spatial overlap area or a spatial overlap area smaller than a threshold exists between each of the multiple independent images;

acquiring, according to the information of each of the multiple independent images, multiple image correction parameters, each image correction parameter corresponding to one of the multiple cameras and allowing multiple adjacent independent images to be corrected into a single contiguous image; and

performing, according to at least one of the multiple image correction parameters acquired according to the information of each of the multiple independent imam, correction processing on video data acquired by at least one of the multiple cameras that corresponds to at least one of the multiple image correction parameters.

2. The method according to claim 1, wherein the acquiring information of the multiple independent images comprises:

sending a capturing command to an image capturing system to which each of the multiple cameras belongs;

receiving the information of the multiple independent images from the image capturing system to which each of the multiple cameras belongs; and

wherein acquiring, according to the information of each of the multiple independent images, the multiple image correction parameters comprises acquiring, according to the information of each of the multiple independent images, at least one of multiple geometric correction parameters each corresponding to one of the multiple cameras and multiple color correction parameters each corresponding to one of the multiple cameras; and

wherein performing, according to at least one of the multiple image correction parameters acquired according to the information of each of the multiple independent images, correction processing on video data acquired by at least one of the multiple cameras that corresponds to the at least one of the multiple image correction parameters comprises performing, according to at least one of the multiple geometric correction parameters and the multiple color correction parameters, correction processing on the video data acquired by the at least one of the multiple cameras.

3. The method according to claim 2, wherein acquiring, according to the information of each of the multiple independent images, the multiple geometric correction parameters each corresponding to one of the multiple cameras comprises:

performing joint correction processing on the information of each of the multiple independent images, acquiring information of each of multiple corrected images corresponding to the information of each of the multiple independent images, wherein multiple adjacent corrected images form a single contiguous image, and acquiring each of the multiple geometric correction parameters according to the information of at least one of the multiple corrected images and information of at least one corresponding independent image.

4. The method according to claim 3, wherein the performing joint correction processing on the information of each of the multiple independent images comprises:

selecting information of one image from the information of the multiple independent images as base image information;

performing the correction processing on the base image information to produce corrected base image information; and

using the corrected base image information as reference image information to perform the correction processing on information of each of other independent images.

5. The method according to claim 4, wherein before sending the capturing command to the image capturing system to which each of the multiple cameras belongs, the method further comprises sending a position adjustment instruction to each of the multiple cameras, so that each camera of the multiple cameras is aligned with each of the other cameras of the multiple cameras.

6. The method according to claim 2, wherein sending the capturing command to an image capturing system to which each of the multiple cameras belongs, and receiving the information of the multiple independent images from the image capturing system to which each of the multiple cameras belongs comprises:

sending, to the image capturing system to which each of the multiple cameras belongs, the capturing command, wherein the capturing command includes a command for shooting template images,

receiving information of the multiple template images, wherein the multiple template images are captured at multiple exposure times and sent by at least one of the multiple cameras; and

wherein acquiring, according to the information of each of the multiple independent images, the multiple color correction parameters each corresponding to one of the multiple cameras comprises;

acquiring, according to the information of the multiple template images, at least one color correction parameter corresponding to at least one of the multiple cameras.

7. The method according to claim 6, wherein acquiring, according to the information of the multiple template images, at least one color correction parameter corresponding to at least one of the multiple cameras comprises:

acquiring levels of pixel color component values of at least one adjacent image area in each of the multiple exposure times according to the information of the multiple template images;

performing interpolation processing on levels of pixel color component values of each adjacent image area in at least one of the multiple exposure times to acquire a grading curve of pixel color component values of each camera in the at least one of the multiple exposure times; and

acquiring a color and brightness correction parameter of the at least one of the multiple cameras according to a target curve and the acquired grading curve of the pixel color component values.

8. The method according to claim 7, wherein the target curve comprises one of the group consisting of:

(a) a grading curve of the color component values, (b) an average curve of the grading curves of the color component values, and (c) a pixel reference distribution curve.

9. The method according to claim 7, wherein performing correction processing on the video data of the corresponding camera according to the color correction parameter comprises:

determining a color look up table according to the color correction parameter, and

performing the correction processing on the video data according to the color look up table.

10. The method according to claim 6, wherein acquiring, according to the information of the multiple template images, at least one color correction parameter corresponding to at least one of the multiple cameras comprises:

acquiring, according to the information of the multiple template images, levels of color component values of at least one adjacent image areas between multiple image partitions inside at least one camera in at least one of the multiple exposure times;

performing interpolation processing on the levels of color component values of the at least one adjacent image area in the at least one exposure time to acquire a grading curve of color component values of at least one image partition in the at least one exposure time; and

acquiring a color correction parameter of the at least one image partition inside the at least one camera according to a target curve and the acquired grading curve of the color component values.

11. The method according to claim 10, wherein the target curve comprises one of the group consisting of:

(a) a grading curve of the color component values, (b) an average curve of the grading curves of the color component values, and (c) a pixel reference distribution curve.

12. The method according to claim 10, wherein performing correction processing on the video data of the corresponding camera according to the color correction parameter comprises:

determining a color look up table according to the color correction parameter, and

performing the correction processing on the video data according to the color look up table.

13. The method according to claim 6, wherein performing correction processing on the video data of the corresponding camera according to the color correction parameter comprises:

determining a color look up table according to the color correction parameter, and

performing the correction processing on the video data according to the color look up table.

14. A device for performing image correction on multiple independent images, the device comprising:

an acquiring module, configured to;

acquire information of the multiple independent images wherein each of the multiple independent images is captured by one of multiple cameras and wherein no spatial overlap area or a spatial overlap area smaller than a threshold exists between each of the multiple independent images, and

acquire, according to the information of each of the multiple independent images, multiple image correction parameters, each image correction parameter corresponding to one of the multiple cameras and allowing multiple adjacent independent images to be corrected into a single contiguous image; and

a processing module, configured to perform, according to at least one of the multiple image correction parameters acquired by the acquiring module according to the information of each of the multiple independent images, correction processing on video data acquired by at least one of the multiple cameras that corresponds to at least one of the multiple image correction parameter.

15. The device according to claim 14, wherein the acquiring module comprises:

a first acquiring unit, configured to send a capturing command to an image capturing system to which each of the multiple cameras belongs and receive the information of the multiple independent images from the image capturing system;

a second acquiring unit, configured to acquire, according to the information of the multiple independent images received by the first acquiring unit, one of;

multiple geometric correction parameters, each corresponding to one of the multiple cameras and multiple color correction parameters, each corresponding to one of the multiple cameras; and

wherein the processing module is configured to perform, on the video data acquired by the at least one of the multiple cameras that corresponds to at least one of the multiple image correction parameters, correction processing according to at least one of the multiple geometric correction parameters and the multiple color correction parameters.

16. The device according to claim 15, wherein the second acquiring unit is configured to perform joint correction processing on the information of the multiple independent images, acquire information of multiple corrected images corresponding to the information of the multiple independent images, wherein multiple adjacent corrected images form a single contiguous image, and acquire each of the multiple geometric correction parameters according to the information of at least one of the multiple corrected images and information of at least one corresponding independent image.

17. The device according to claim 15, wherein the first acquiring unit is configured to:

send, to the image capturing system to which each of the multiple cameras belongs, a capturing command for shooting multiple template images, and

receive information of the multiple template images exposed at a multiple exposure time, wherein each of the multiple template images captured and sent by one of the multiple cameras; and

the second acquiring module is configured to;

acquire levels of color component values of each adjacent image area between each camera in each of multiple exposure times according to the information of multiple template images exposed at each of the multiple exposure times;

perform interpolation processing on the levels of color component values of each adjacent image area in each of the multiple exposure times to acquire a grading curve of pixel color component values of each camera in each exposure time; and

acquire a color and brightness correction parameter of each of the multiple cameras according to a target curve and a corresponding grading curve of pixel color component values.

18. The device according to claim 15, wherein the first acquiring unit is configured to:

send, to the image capturing system to which each of the multiple cameras belongs, a capturing command for shooting multiple template images, and

receive information of the multiple template images exposed at a multiple exposure time, wherein each of the multiple template images captured and sent by one of the multiple cameras; and

the second acquiring module is configured to;

acquire, according to the information of the template images exposed at multiple exposure times, levels of color component values of adjacent image areas between multiple image partitions inside each camera in each of the multiple exposure times;

perform interpolation processing on the levels of color component values of each image area in each exposure time to acquire a grading curve of color component values of each image partition in each exposure time; and

acquire a color correction parameter of each image partition inside each of the multiple cameras according to a target curve and a corresponding grading curve of color component values.