CAR NAVIGATION SYSTEM

• US 20100121561A1
• Filed: 01/25/2008
• Published: 05/13/2010
• Est. Priority Date: 01/29/2007
• Status: Active Grant

• Current Assignee: Toshiba Solutions Corporation (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation), Toshiba Solutions Corporation (Toshiba Corporation)
• Inventors: Suzuki, Tomohisa, Mizutani, Hiroyuki, Kodaira, Naoaki
• Granted Patent: US 8,175,806 B2
• Time in Patent Office: Days
• US Class Current: 701/200
• CPC Class Codes: G01C 11/02 Picture taking arrangements specially adapted for photogrammetry or photographic surveying, e.g. controlling overlapping of pictures
• CPC Class Codes: G01C 21/26 specially adapted for navigation in a road network
• CPC Class Codes: G06V 20/588 Recognition of the road, e.g. of lane markings; Recognition of the vehicle driving pattern in relation to the road
• CPC Class Codes: G08G 1/09623 Systems involving the acquisition of information from passive traffic signs by means mounted on the vehicle G08G1/0967 takes precedence
• CPC Class Codes: G08G 1/096716 where the received information does not generate an automatic action on the vehicle control
• CPC Class Codes: G08G 1/09675 where a selection from the received information takes place in the vehicle
• CPC Class Codes: G08G 1/096783 where the origin of the information is a roadside individual element
• CPC Class Codes: G08G 1/0969 having a display in the form of a map
• CPC Class Codes: H04N 5/272 Means for inserting a foreground image in a background image, i.e. inlay, outlay
• CPC Class Codes: H04N 7/18 Closed-circuit television [CCTV] systems, i.e. systems in which the video signal is not broadcast

Abstract

To improve recognition accuracy of a traveling direction of a vehicle by accurately detecting a marking on a road surface which is photographed by a camera while a road environment where a vehicle travels is changing. A car navigation system 100 detects an image of a light-irradiated portion which is unnecessary for the recognition of a road marking, in an image behind a vehicle captured by a camera 6 mounted on the vehicle, clips out image areas in a predetermined shape excluding the detected image area, and sequentially stores the clipped images in a storage unit 7b. Then, the new clipped image and the clipped image already stored in the storage unit 7b are combined, and an image of a road marking is detected and recognized from the composite image.

Claims

1. A car navigation system, comprising:

a camera mounted on a vehicle, with a shooting direction directed forward or backward from the vehicle, and capturing an image including at least a road surface in front of or behind the vehicle;

a storage unit in which the image captured by said camera is stored;

a first image processing unit detecting an area unnecessary for recognition of a road marking included in the image captured by said camera;

a second image processing unit combining an old image already stored in said storage unit or a partial image area of the old image as a complement for the unnecessary area detected in the image by said first image processing unit, to generate a composite image; and

a marking recognizing unit detecting and recognizing the road marking painted on the road surface by using the composite image generated by said second image processing unit and pre-set marking information.

6. The car navigation system according to claim 1,

wherein said first image processing unit or said unnecessary area detecting unit detects an image area where an object unnecessary for the recognition of the road marking is present, by comparing the new image area stored in said storage unit and several old image areas already stored in said storage unit;

and

wherein said second image processing unit or said image combining unit combines an image area which is extracted from the old image area stored in said storage unit and not including the unnecessary object, in place of the detected image area of the unnecessary object.

8. The car navigation system according to claim 6, comprising,

an erasing unit erasing, from the composite image, the image area of the unnecessary object detected by said first image processing unit or said unnecessary area detecting unit.

2. A car navigation system, comprising:

a camera mounted on a rear part of the vehicle, with a shooting direction directed backward from the vehicle and capturing a video including at least a road surface behind the vehicle;

a storage unit in which an image is storable; and

a screen downloading unit sequentially downloading the videos captured by said camera into said storage unit at predetermined time intervals in a unit of a screen;

an unnecessary area detecting unit detecting an area unnecessary for recognition of a road marking included in the image of the screen downloaded into said storage unit;

an image clip-out unit clipping out an image area in a predetermined shape not including the unnecessary area detected by said unnecessary area detecting unit, to store the clipped image area into said storage unit;

a movement amount calculating unit calculating a movement amount by comparing the new image area stored in said storage unit by said image clip-out unit and an immediately preceding old image area already stored in said storage unit;

an image combining unit generating a composite image by combining the new and old image areas according to the movement amount of the road marking calculated by said movement amount calculating unit; and

a road marking recognizing unit detecting and recognizing the road marking by using the composite image generated by said image combining unit and pre-set marking information.

3. The car navigation system according to claim 2,

wherein said image clip-out unit includes a clipped image changing unit changing a shape or an arrangement of the image area which is to be clipped out from the image of the screen, according to the movement amount calculated by said movement amount calculating unit.

4. The car navigation system according to claim 3,

wherein said clipped image changing unit changes a position of the image area which is to be clipped out from the image of the screen, according to a detected state or a recognized state of the road marking included in the composite image.

5. The car navigation system according to claim 3,

wherein the clipped image changing unit changes a position of the image area which is to be clipped out from the image of the screen, depending on time.

7. The car navigation system according to claim 2,

wherein said first image processing unit or said unnecessary area detecting unit detects an image area where an object unnecessary for the recognition of the road marking is present, by comparing the new image area stored in said storage unit and several old image areas already stored in said storage unit;

and

wherein said second image processing unit or said image combining unit combines an image area which is extracted from the old image area stored in said storage unit and not including the unnecessary object, in place of the detected image area of the unnecessary object.

9. The car navigation system according to claim 7, comprising an erasing unit erasing, from the composite image, the image area of the unnecessary object detected by said first image processing unit or said unnecessary image detecting unit.