Imaging processing device and a method of processing an image

• US 7,557,858 B2
• Filed: 10/14/2004
• Issued: 07/07/2009
• Est. Priority Date: 10/15/2003
• Status: Expired due to Fees

• Current Assignee: Fujitsu Ten Limited (DENSO Corporation)
• Original Assignee: Fujitsu Ten Limited (DENSO Corporation)
• Inventors: Honda, Kanako F., Shima, Nobukazu
• Primary Examiner(s): Ometz; David L
• Assistant Examiner(s): Jerabek; Kelly L
• Application Number:
  US10/963,664
• Publication Number:
  US 20050083432A1
• Time in Patent Office: 1,727 Days
• Field of Search: 348/241, 348/243, 348246-248, 348362-366, 382/168
• US Class Current: 348/362
• CPC Class Codes: H04N 23/634 Warning indications
• CPC Class Codes: H04N 23/70 Circuitry for compensating brightness variation in the scene
• CPC Class Codes: H04N 23/73 by influencing the exposure time

Abstract

An image processing device includes a camera that picks up an image, an image density recognizer that recognizes density of the image, and an exposure controller that in an exposure control period automatically controls an exposure of the camera based on the density recognized. The exposure controller period includes at least a maximum exposure period during which the exposure is set to a maximum exposure, a minimum exposure period during which the exposure is set to a minimum exposure, and a normal exposure period during which the exposure is set to in between the maximum exposure and the minimum exposure.

Claims

1. An image processing device comprising:

an imaging unit that picks up an image;

an image density recognizer that recognizes density of the image; and

an exposure controller that in an exposure control period automatically controls an exposure of the imaging unit based on the density recognized, wherein the exposure control period includes at least a maximum exposure period during which the exposure is set to a maximum exposure, a minimum exposure period during which the exposure is set to a minimum exposure, and a normal exposure period during which the exposure is set to in between the maximum exposure and the minimum exposure; and

a problem recognizer that determines any one of whether the imaging unit is abnormal and whether an environment is unsuitable for picking up an image by the imaging unit based on densities of images, which are recognized by the image density recognizer, that are picked up during the maximum exposure period, the minimum exposure period, and/or the normal exposure period, wherein

the maximum exposure period, the minimum exposure period, and the normal exposure period have substantially same time length and appear in a predetermined order in the exposure control period.

2. The image processing device according to claim 1, wherein

the normal exposure period is longer than the maximum exposure period and the minimum exposure period.

3. The image processing device according to claim 1, wherein the problem recognizer determines that the exposure during the normal exposure period is unsuitable when

densities of the image, which is recognized by the image density recognizer, that is picked up during the normal exposure period show a smear or a ghost as a false signal occurs and when the densities of the image, which is recognized by the image density recognizer, that is picked up during the minimum exposure period do not show a smear or a ghost.

4. The image processing device according to claim 1, wherein the problem recognizer determines any one of that the imaging unit is abnormal and the environment is unsuitable for picking up an image by the imaging unit when

an image picked up during the maximum exposure period has a dark density loss or when an image picked up during the minimum exposure period has a bright density loss.

5. The image processing device according to claim 1, wherein

when an image picked up during the maximum exposure period has a dark density loss, the problem recognizer determines, after changing the imaging environment such that an image picked up at the maximum exposure does not have a dark density loss, that

the imaging unit is abnormal when, an image picked up during the maximum exposure period has a dark density loss, and

the environment is unsuitable for picking up an image by the imaging unit when the image does not have a dark density loss.

6. The image processing device according to claim 1, wherein

an imaging environment in which an image picked up during the maximum exposure period does not have a dark density loss is an imaging environment in which the imaging unit picks up a predetermined image of a light source.

7. The image processing device according to claim 1, wherein

when an image picked up during the minimum exposure period has a bright density loss, the image recognizer determines, after changing the imaging environment such that an image picked up at the minimum exposure does not have a bright density loss, that

the imaging unit is abnormal when an image picked up during the maximum exposure period has a bright density loss, and

the environment is unsuitable for picking up an image by the imaging unit when the image does not have a bright density loss.

8. The image processing device according to claim 1, wherein

an imaging environment in which an image picked up during the minimum exposure period does not have a bright density loss is an imaging environment in which the imaging unit picks up an image by cutting a light source.

9. The image processing device according to claim 1, wherein the imaging unit picks up an image according to an interlace system of scanning twice including an odd-line scan and an even-line scan,

wherein the image density recognizer recognizes density using an image obtained by scanning one time.

10. The image processing device according to claim 9, wherein the problem recognizer determines whether a dark density loss occurs based on an image obtained at a first scanning, and determines whether the imaging unit is abnormal or the imaging environment is unsuitable based on an image obtained at a second scanning.

11. The image processing device according to claim 9, wherein the problem recognizer determines whether a bright density loss occurs based on an image obtained at a first scanning, and determines whether the imaging unit is abnormal or the imaging environment is unsuitable based on an image obtained at a second scanning.

12. The image processing device according to claim 1, further comprising an alarm unit that notifies an abnormality of the imaging unit when the problem recognizer determines that the imaging unit is abnormal.

13. An image processing device comprising:

an image obtaining unit that includes any one of an imaging unit that picks up an image of a surrounding of a vehicle and from an external device receives an image of a surrounding of a vehicle picked up by an imaging unit;

an exposure controller that during an exposure control period automatically controls an exposure of the imaging unit based on a density distribution of an image obtained by the image obtaining unit, wherein the exposure automatic control period includes at least a maximum exposure period during which the exposure is set to a maximum exposure, a minimum exposure period during which the exposure is set to a minimum exposure, and a normal exposure period during which the exposure is set to in between the maximum exposure and the minimum exposure;

a determining unit that determines at least one of whether the imaging unit is abnormal and whether an environment is unsuitable for picking up an image by the imaging unit, based on densities of images that are picked up during the maximum exposure period, the minimum exposure period, and the normal exposure period; and

an output unit that outputs a result of determination made by the determining unit to an external vehicle-controlling device.

14. The image processing device according to claim 13, further comprising a timing changer that changes lengths and/or positions in the exposure automatic control period of the maximum exposure period, the minimum exposure period, and/or the normal exposure period.

15. The image processing device according to claim 14, wherein the imaging unit is fixed to a vehicle, and

the image processing device further comprising a timing setting unit that controls the timing changer so as to set the lengths and/or the positions based on at least one of a state of the vehicle, conditions around the vehicle, and usage of a picked-up image.

16. A method of processing an image, comprising:

picking up an image;

recognizing a density of the image; and

controlling automatically an exposure in an exposure control period at the picking up based on the density recognized, wherein the exposure control period includes at least a maximum exposure period during which the exposure is set to a maximum exposure, a minimum exposure period during which the exposure is set to a minimum exposure, and a normal exposure period during which the exposure is set to in between the maximum exposure and the minimum exposure; and

determining any one of whether the picking up is abnormal and whether an environment is unsuitable for the picking up based on densities of images recognized that are picked up during the maximum exposure period, the minimum exposure period, and/or the normal exposure period, wherein

the maximum exposure period, the minimum exposure period, and the normal exposure period have substantially same time length and appear in a predetermined order in the exposure control period.

17. A method of processing an image, comprising:

picking up an image of a surrounding of a vehicle;

receiving an image of a surrounding of a vehicle from an external device;

controlling automatically an exposure in an exposure control period at the picking up based on density distributions of the image picked up and the image received from the external device, wherein the exposure automatic control period includes at least a maximum exposure period during which the exposure is set to a maximum exposure, a minimum exposure period during which the exposure is set to a minimum exposure, and a normal exposure period during which the exposure is set to a minimum exposure and a normal exposure period during which the exposure is set to in between the maximum exposure and the minimum exposure;

determining at least one of whether the picking up is abnormal and whether an environment is unsuitable for the picking up, based on densities of images that are picked up during the maximum exposure period, the minimum exposure period, and the normal exposure period; and

outputting a result of the determining to an external vehicle-controlling device.