Apparatus and method for correcting image distortion of a camera for vehicle

• US 9,813,619 B2
• Filed: 12/09/2014
• Issued: 11/07/2017
• Est. Priority Date: 07/24/2014
• Status: Active Grant

• Current Assignee: Hyundai Motor Company (Hyundai Motor Group)
• Original Assignee: Hyundai Motor Company (Hyundai Motor Group)
• Inventors: An, Jun Sik, Lee, Joong Ryoul, Sung, Kap Je, Chang, Eu Gene
• Primary Examiner(s): Elahi, Shan
• Application Number:
  US14/564,751
• Publication Number:
  US 20160027158A1
• Time in Patent Office: 1,064 Days
• Field of Search: 348148
• CPC Class Codes: G06T 2207/30252 Vehicle exterior; Vicinity of vehicle
• 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

Abstract

An apparatus for correcting image distortion of a camera in a vehicle includes: a camera mounted in the vehicle; a camera characteristic extractor configured to extract camera characteristic parameters of the camera based on a preset mathematical model; a tilt angle calculator configured to calculate tilt angles of a virtual camera corresponding to the camera in each photographing region using the camera characteristic parameters; a yaw angle calculator configured to calculate yaw angles of the virtual camera in each photographing region; an image corrector configured to view-transform a photographed image photographed by the camera by adjusting angles of the virtual camera based on a correction model in order to secure a view region of the photographed image and create a corrected image depending on the view-transform; and a display configured to display the corrected image output from the image corrector.

Claims

1. An apparatus for correcting image distortion of a camera in a vehicle, comprising:

a camera mounted in the vehicle;

a controller configured to;

extract camera characteristic parameters of the camera based on a correction coefficient for correcting image distortion;

calculate a tilt angle of a virtual camera corresponding to the camera in one or more photographing regions using the camera characteristic parameters;

calculate a yaw angle of the virtual camera in each of the one or more photographing regions;

create a correction model by applying the calculated tilt angle and calculated the yaw angle of the virtual camera in each of the one or more photographing regions;

view-transform a photographed image photographed by the camera by adjusting the tilt angle and the yaw angle of the virtual camera based on the created correction model to secure a view region of the photographed image and create a corrected image depending on the view transformation; and

display the corrected image on a display disposed within the vehicle.

2. The apparatus for correcting image distortion of a camera in a vehicle according to claim 1, wherein the tilt angle is an angle at which the camera is tilted toward the ground with respect to a line that is parallel to the ground.

3. The apparatus for correcting image distortion of a camera in a vehicle according to claim 1, wherein the yaw angle is an angle at which the camera is rotated toward the left or the right with respect to a line that is perpendicular to a surface on which the camera is mounted.

4. The apparatus for correcting image distortion of a camera in a vehicle according to claim 1, wherein the correction model is implemented as any one of:

a pin hole projection model, a spherical projection model, a cylindrical projection model, and a plane projection model.

5. The apparatus for correcting image distortion of a camera in a vehicle according to claim 1, wherein the camera characteristic parameters are divided into camera extrinsic parameters and camera intrinsic parameters.

6. The apparatus for correcting image distortion of a camera in a vehicle according to claim 5, wherein the camera extrinsic parameters include information relating to mounting characteristics of the camera including an installation height of the camera and a direction of the camera.

7. The apparatus for correcting image distortion of a camera in a vehicle according to claim 5, wherein the camera intrinsic parameters include information relating to optical characteristics of the camera including a focal length of the camera, a principal point of the camera, and a skew coefficient of the camera.

8. The apparatus for correcting image distortion of a camera in a vehicle according to claim 1, wherein the image corrector is further configured to adjust the tilt angle and the yaw angle of the virtual camera depending on the tilt angle and the yaw angle in each of the one or more photographing regions to view-transform the photographed image.

9. The apparatus for correcting image distortion of a camera in a vehicle according to claim 1, wherein the camera is a wide angle camera.

10. A method for correcting image distortion of a camera in a vehicle, comprising:

extracting, by a controller, camera characteristic parameters of the camera which is mounted in the vehicle based on a correction coefficient for correcting image distortion;

calculating, by the controller, a tilt angle and a yaw angle of a virtual camera corresponding to the camera in one or more photographing regions using the camera characteristic parameters;

creating, by the controller, a correction model by applying the calculated tilt angle and the calculated yaw angle in each of the one or more photographing regions;

adjusting, by the controller, an angle of the virtual camera based on the created correction model in order to secure a view region of a photographed image photographed by the camera;

view-transforming, by the controller, the photographed image by adjusting the tilt angle and the yaw angle of the virtual camera based on the created correction model to secure a view region of the photographed image and create a corrected image depending on the view-transformation; and

displaying, by the controller, the corrected image on a display disposed within the vehicle.

11. The method for correcting image distortion of a camera in a vehicle according to claim 10, wherein each of the one or more photographing regions is a region in a pixel unit.

12. The method for correcting image distortion of a camera in a vehicle according to claim 10, wherein the tilt angle is an angle at which the camera is tilted toward the ground with respect to a line that is parallel to the ground.

13. The method for correcting image distortion of a camera in a vehicle according to claim 10, wherein the yaw angle is an angle at which the camera is rotated toward the left or the right with respect to a line that is perpendicular to a surface on which the camera is mounted.

14. The method for correcting image distortion of a camera in a vehicle according to claim 10, wherein in the adjusting of the angle of the virtual camera, the tilt angle and the yaw angle of the virtual camera are adjusted depending on the tilt angle and the yaw angle in each of the one or more photographing regions.

15. The method for correcting image distortion of a camera in a vehicle according to claim 10, wherein the camera is a wide angle camera.

16. A non-transitory computer readable medium containing program instructions executed by a controller for correcting image distortion of a camera in a vehicle, the computer readable medium comprising:

program instructions that extract camera characteristic parameters of the camera which is mounted in the vehicle based on a correction coefficient for correcting image distortion;

program instructions that calculate a tilt angle and a yaw angle of a virtual camera corresponding to the camera in one or more photographing regions using the camera characteristic parameters;

program instructions that create a correction model by applying the calculated tilt angle and the calculated yaw angle in each of the one or more photographing regions;

program instructions that adjust an angle of the virtual camera based on the created correction model in order to secure a view region of a photographed image photographed by the camera;

program instructions that view-transform the photographed image by adjusting the tilt angle and the yaw angle of the virtual camera based on the created correction model to secure a view region of the photographed image and create a corrected image depending on the view-transformation; and

program instructions that display the corrected image on a display disposed within the vehicle.