Double exposure camera system of vehicle and image acquisition method thereof

• US 20040227814A1
• Filed: 08/15/2003
• Published: 11/18/2004
• Est. Priority Date: 05/15/2003
• Status: Abandoned Application

• Current Assignee: Hyundai Motor Company (Hyundai Motor Group)
• Original Assignee: Hyundai Motor Company (Hyundai Motor Group)
• Inventors: Choi, Jang Don
• Application Number:
  US10/642,001
• Publication Number:
  US 20040227814A1
• Time in Patent Office: Days
• US Class Current: 348/148
• CPC Class Codes: B60R 1/00 Optical viewing arrangements; Real-time viewing arrangements for drivers or passengers using optical image capturing systems, e.g. cameras or video systems specially adapted for use in or on vehicles
• CPC Class Codes: B60R 2300/106 using night vision cameras
• CPC Class Codes: B60R 2300/8053 for bad weather conditions or night vision
• CPC Class Codes: G07C 5/0891 Video recorder in combination with video camera
• CPC Class Codes: H04N 23/71 Circuitry for evaluating the brightness variation
• CPC Class Codes: H04N 23/73 by influencing the exposure time
• CPC Class Codes: H04N 23/741 by increasing the dynamic range of the image compared to the dynamic range of the electronic image sensors

Abstract

Regarding a double exposure scheme that synthesizes first and second images respectively obtained by first and second exposure periods for obtaining a final image outside of a vehicle, at least one adjusting parameter is calculated and thereby at least one of the first and second exposure periods is adjusted on the basis of the adjusting parameter.

Claims

1. A camera system for obtaining an image outside of a vehicle, comprising:

a camera;

an image synthesizer for receiving a plurality of initial images including first and second images according to first and second exposure periods respectively, and for synthesizing the received first and second images; and

a control unit for controlling the camera, the control unit calculating at least one adjusting parameter and adjusting at least one of the first and second exposure periods of the camera on the basis of the adjusting parameter.

2. The camera system of claim 1, wherein the at least one adjusting parameter comprises at least one vehicle parameter that varies according to a running state of the vehicle.

3. The camera system of claim 2, further comprising a vehicle speed detector for detecting a speed of the vehicle, wherein the vehicle parameter comprises the vehicle speed.

4. The camera system of claim 2, further comprising a lateral acceleration detector for detecting a lateral acceleration of the vehicle, wherein the vehicle parameter comprises the lateral acceleration.

5. The camera system of claim 2, further comprising a steering angle detector for detecting a steering angle of the vehicle, wherein the vehicle parameter comprises the steering angle.

6. The camera system of claim 2, further comprising a wiper speed detector for detecting a wiper speed of the vehicle, wherein the vehicle parameter comprises the wiper speed.

7. The camera system of claim 2, further comprising a brightness detector for detecting a brightness outside of the vehicle, wherein the vehicle parameter comprises the outside brightness.

8. The camera system of claim 2, further comprising a navigation system for determining at least one of a current time and a current driving region, wherein the vehicle parameter comprises the at least one of the current time and the current driving region.

9. The camera system of claim 2, wherein the vehicle parameter comprises at least two among a vehicle speed, a lateral acceleration, a steering angle, a wiper speed, a brightness outside of the vehicle, and a current time and/or a current driving region of a navigation system.

10. The camera system of claim 1, wherein the at least one adjusting parameter comprises at least one image parameter obtained on the basis of at least one image of the first and second images.

11. The camera system of claim 10, wherein the image parameter comprises an area index corresponding to an area having luminance greater than a predetermined luminance on the at least one image.

12. The camera system of claim 11, wherein:

the control unit determines whether the area index is greater than a predetermined value; and

the control unit adjusts the exposure period of the at least one image when the area index is greater than the predetermined value.

13. The camera system of claim 10, wherein the image parameter comprises an area index corresponding to an area having luminance less than a predetermined luminance on the at least one image.

14. The camera system of claim 13, wherein:

the control unit determines whether the area index is greater than a predetermined value; and

the control unit adjusts the exposure period of the at least one image when the area index is greater than the predetermined value.

15. The camera system of claim 10, wherein the image parameter comprises a luminance index of maximum frequency corresponding to a most frequent luminance of pixels on the at least one image.

16. The camera system of claim 15, wherein:

the control unit compares the luminance index of maximum frequency with a predetermined range; and

the control unit adjusts the exposure period of the at least one image when the luminance index of maximum frequency is out of the predetermined range.

17. The camera system of claim 10, wherein:

the image parameter comprises a luminance index of an oncoming lane corresponding to whether a region having luminance greater than a predetermined luminance exists in a portion corresponding to the oncoming lane in the at least one image; and

the control unit adjusts the exposure period of the at least one image when the luminance index of the oncoming lane indicates that the region having luminance greater than the predetermined luminance exists in the portion corresponding to the oncoming lane in the at least one image.

18. The camera system of claim 10, wherein:

the image parameter comprises a luminance index of a shoulder region corresponding to whether a region having luminance greater than a predetermined luminance exists in a portion outside vehicle lanes in the at least one image; and

the control unit adjusts the exposure period of the at least one image when the luminance index of the shoulder region indicates that the region having luminance greater than the predetermined luminance exists in the portion outside the vehicle lanes in the at least one image.

19. The camera system of claim 10, wherein the image parameter comprises at least two among:

a first area index corresponding to an area having luminance greater than a predetermined luminance on the at least one image;

a second area index corresponding to an area having luminance less than a predetermined luminance on the at least one image;

a luminance index of maximum frequency corresponding to a most frequent luminance of pixels on the at least one image;

a luminance index of an oncoming lane corresponding to whether a region having luminance greater than a predetermined luminance exists in a portion corresponding to the oncoming lane in the at least one image; and

a luminance index of a shoulder region corresponding to whether a region having luminance greater than a predetermined luminance exists in a portion outside vehicle lanes in the at least one image.

20. The camera system of claim 1, wherein the at least one adjusting parameter comprises at least one vehicle parameter that varies according to a running state of the vehicle and at least one image parameter obtained on the basis of at least one image of the first and second images.

21. A method for obtaining an image outside of a vehicle using a camera system, comprising:

obtaining a first image at a first exposure period;

obtaining a second image at a second exposure period;

synthesizing the first and second images;

calculating at least one adjusting parameter; and

adjusting at least one of the first and second exposure periods on the basis of the adjusting parameter.

22. The method of claim 21, wherein the at least one adjusting parameter comprises at least one vehicle parameter that varies according to a running state of the vehicle.

23. The method of claim 22, wherein the vehicle parameter comprises at least one among a vehicle speed, a lateral acceleration, a steering angle, a wiper speed, a brightness outside of the vehicle, and a current time and/or a current driving region of a navigation system.

24. The method of claim 21, wherein the at least one adjusting parameter comprises at least one image parameter obtained on the basis of at least one image of the first and second images.

25. The method of claim 24, wherein the image parameter comprises at least one among:

a first area index corresponding to an area having luminance greater than a predetermined luminance on the at least one image;

a second area index corresponding to an area having luminance less than a predetermined luminance on the at least one image;

a luminance index of maximum frequency corresponding to a most frequent luminance of pixels on the at least one image;

a luminance index of an oncoming lane corresponding to whether a region having luminance greater than a predetermined luminance exists in a portion corresponding to the oncoming lane in the at least one image; and

a luminance index shoulder region corresponding to whether a region having luminance greater than a predetermined luminance exists in a portion outside vehicle lanes in the at least one image.

26. The method of claim 25, wherein the image parameter comprises an area index corresponding to an area having luminance greater than a predetermined luminance on the at least one image, and the adjusting at least one of the first and second exposure periods comprises:

determining whether the area index is greater than a predetermined value; and

adjusting the exposure period of the at least one image when the area index is greater than the predetermined value.

27. The method of claim 25, wherein the image parameter comprises an area index corresponding to an area having luminance less than a predetermined luminance on the at least one image, and the adjusting at least one of the first and second exposure periods comprises:

determining whether the area index is greater than a predetermined value; and

adjusting the exposure period of the at least one image when the area index is greater than the predetermined value.

28. The method of claim 25, wherein the image parameter comprises a luminance index of maximum frequency corresponding to a most frequent luminance of pixels on the at least one image, and the adjusting at least one of the first and second exposure periods comprises:

comparing the luminance index of maximum frequency with a predetermined range; and

adjusting the exposure period of the at least one image when the luminance index of maximum frequency is out of the predetermined range.

29. The method of claim 25, wherein:

the image parameter comprises a luminance index of an oncoming lane corresponding to whether a region having luminance greater than a predetermined luminance exists in a portion corresponding to the oncoming lane in the at least one image; and

the adjusting at least one of the first and second exposure periods adjusts the exposure period of the at least one image when the luminance index of the oncoming lane indicates that the region having luminance greater than the predetermined luminance exists in the portion corresponding to the oncoming lane in the at least one image.

30. The method of claim 25, wherein:

the image parameter comprises a luminance index of a shoulder region corresponding to whether a region having luminance greater than a predetermined luminance exists in a portion outside vehicle lanes in the at least one image; and

the adjusting at least one of the first and second exposure periods adjusts the exposure period of the at least one image when the luminance index of the shoulder region indicates that the region having luminance greater than the predetermined luminance exists in the portion outside vehicle lanes in the at least one image.

31. The method of claim 21, wherein the at least one adjusting parameter comprises at least one vehicle parameter that varies according to a running state of the vehicle and at least one image parameter obtained on the basis of at least one image of the first and second images.