Image calibration system and calibration method of a stereo camera

1. A calibration method of a stereo camera, wherein the stereo camera comprises a first image capture unit and a second image capture unit, the calibration method comprising:

transmitting a group of default system parameters of the stereo camera from the stereo camera to a server;

downloading a calibration pattern corresponding to the group of default system parameters from the server;

calculating a plurality of camera calibration parameters corresponding to the stereo camera according to the calibration pattern; and

executing an image rectification operation on the first image capture unit and the second image capture unit according to the plurality of camera calibration parameters, respectively, wherein the server does not change the group of default system parameters transmitted from the stereo camera to the server during the image rectification operation being executed on the first image capture unit and the second image capture unit, and the group of default system parameters is not changed with a first image captured by the first capture unit and a second image captured by the second capture unit.

2. The calibration method of claim 1 , wherein a processor of the stereo camera transmits the group of default system parameters to the server through a calibration program, and the calibration program is built in the stereo camera, or the processor of the stereo camera downloads the calibration program from the server.

3. The calibration method of claim 1 , wherein calculating the plurality of camera calibration parameters corresponding to the stereo camera according to the calibration pattern comprises:

the first image capture unit and the second image capture unit executing an image capture operation on the calibration pattern respectively to generate a first image and a second image corresponding to the calibration pattern when the calibration pattern displayed by a display is located within an image calibration range of the stereo camera;

generating projection parameters corresponding to the calibration pattern according to a first image and a second image corresponding to the calibration pattern, respectively; and

calculating the plurality of camera calibration parameters according to the projection parameters corresponding to the calibration pattern.

4. The calibration method of claim 3 , wherein the display has at least one position marker, and the processor of the stereo camera utilizes at least one alignment marker of another display and the at least one position marker to make the calibration pattern be located within the image calibration range of the stereo camera.

5. The calibration method of claim 3 , wherein the processor of the stereo camera calculates the plurality of camera calibration parameters corresponding to the stereo camera according to the projection parameters corresponding to the calibration pattern.

6. The calibration method of claim 3 , wherein the server calculates the plurality of camera calibration parameters corresponding to the stereo camera according to the projection parameters corresponding to the calibration pattern.

7. The calibration method of claim 3 , wherein the stereo camera is connected to the server through a host and an Internet, and the display is coupled to the host.

8. The calibration method of claim 3 , wherein the stereo camera is connected to the server through an Internet, and the display is coupled to the stereo camera.

9. The calibration method of claim 1 , further comprising:

transmitting an identification parameter corresponding to the stereo camera to the server.

10. The calibration method of claim 1 , wherein the group of default system parameters comprises at least one of a lens focal length, an optical axis, and a lens deformation corresponding to the first image capture unit, a lens focal length, an optical axis, and a lens deformation corresponding to the second image capture unit, a distance between the first image capture unit and the second image capture unit, a number of a plurality of sensing rows of the first image capture unit and a number of a plurality of sensing rows of the second image capture unit, a number of sensing pixels comprised in each of the plurality of sensing rows of the first image capture unit and the plurality of sensing rows of the second image capture unit, and a size of each of the sensing pixels.

11. The calibration method of claim 1 , further comprising:

transmitting default characteristic parameters of a display to the server;

downloading another calibration pattern corresponding to the group of default system parameters and the default characteristic parameters of the display from the server, wherein the display displays the another calibration pattern;

calculating a plurality of camera calibration parameters corresponding to the stereo camera according to the another calibration pattern; and

executing an image rectification operation on the first image capture unit and the second image capture unit according to the plurality of camera calibration parameters, respectively.

12. The calibration method of claim 11 , wherein the default characteristic parameters of the display comprise at least one of a horizontal resolution of the display, a vertical resolution of the display, and a profile and a size of the display.

13. An image calibration system, comprising:

a stereo camera having a first image capture unit, a second image capture unit, and a processor, wherein the processor transmits a group of default system parameters of the stereo camera from the stereo camera to a server, and downloads a calibration pattern corresponding to the group of default system parameters to a display from the server after the server receives the group of default system parameters, wherein the group of default system parameters is not changed with a first image captured by the first capture unit and a second image captured by the second capture unit;

wherein the processor or the server calculates a plurality of camera calibration parameters corresponding to the stereo camera according to the calibration pattern, and the processor executes an image rectification operation on the first image capture unit and the second image capture unit according to the plurality of camera calibration parameters, respectively, wherein the server does not change the group of default system parameters transmitted from the stereo camera to the server during the image rectification operation being executed on the first image capture unit and the second image capture unit.

14. The image calibration system of claim 13 , wherein the processor transmits the group of default system parameters to the server through a calibration program, and the calibration program is built in the stereo camera, or the processor downloads the calibration program from the server.

15. The image calibration system of claim 13 , wherein when the calibration pattern of the calibration pattern displayed by the display is located within an image calibration range of the stereo camera, the first image capture unit and the second image capture unit executes an image capture operation on the calibration pattern respectively to generate a first image and a second image corresponding to the calibration pattern, the processor further generates projection parameters corresponding to the calibration pattern according to a first image and a second image corresponding to the calibration pattern respectively, and the processor or the server calculates the plurality of camera calibration parameters according to the projection parameters corresponding to the calibration pattern.

16. The image calibration system of claim 15 , wherein the display has at least one position marker, and the processor of the stereo camera utilizes at least one alignment marker of another display and the at least one position marker to make the calibration pattern be located within the image calibration range of the stereo camera.

17. The image calibration system of claim 13 , wherein the stereo camera is connected to the server through a host and an Internet, and the display is coupled to the host.

18. The image calibration system of claim 13 , wherein the processor further transmits an identification parameter corresponding to the stereo camera to the server.

19. The image calibration system of claim 13 , wherein the stereo camera is connected to the server through an Internet, and the display is coupled to the stereo camera.

20. An image calibration system, comprising:

a stereo camera having a first image capture unit, a second image capture unit, and a processor, wherein the processor transmits a group of default system parameters of the stereo camera and default characteristic parameters of a display from the stereo camera to a server, and downloads a calibration pattern corresponding to the group of default system parameters and the default characteristic parameters of the display from the server to the display after the server receives the group of default system parameters and the default characteristic parameters of the display, wherein the group of default system parameters is not changed with a first image captured by the first capture unit and a second image captured by the second capture unit;

wherein when the calibration pattern displayed by the display is located within an image calibration range of the stereo camera, the processor or the server calculates a plurality of camera calibration parameters corresponding to the stereo camera according to the calibration pattern, and the processor executes an image rectification operation on the first image capture unit and the second image capture unit according to the plurality of camera calibration parameters, respectively, wherein the server does not change the group of default system parameters of the stereo camera and the default characteristic parameters of the display transmitted from the stereo camera to the server during the image rectification operation being executed on the first image capture unit and the second image capture unit.