Image recognition apparatuses, methods and programs

1. An image recognition apparatus comprising:

a controller configured to:

acquire image information of a plurality of frames of images sensed at predetermined regular time intervals, each image including at least a road surface of an area close to a vehicle;

detect a leading end and a trailing end of a lane mark included in a detection area defined in each frame of the image information;

detect a detected distance from one of the leading end and the trailing end of the lane mark to the other one as a detected distance on the basis of the speed of the vehicle and the number of frames between a frame in which one of the leading end and the trailing end of the lane mark is detected and a frame in which the other one of the leading end and the trailing end of the lane mark is detected; and

determine a lane mark type of the lane mark on the basis of the detected distance.

2. The image recognition apparatus according to claim 1 , wherein the controller detects the detected distance by calculating the distance that the vehicle travels every frame of the image information on the basis of the speed of the vehicle, multiplying the vehicle traveling distance per frame by the number of frames.

3. The image recognition apparatus according to claim 1 , wherein the detection area is a partial area of each frame, the partial area being set to include a location that is common for a plurality of frames of image information.

4. The image recognition apparatus according to claim 1 , wherein the controller determines the lane mark type as a broken line, if the detected distance is in a range from a predetermined lower limit to a predetermined upper limit.

5. The image recognition apparatus according to claim 4 , wherein the controller selects one of a plurality of types of broken-line lane marks that are different in one or both of segment length and segment space.

6. The image recognition apparatus according to claim 4 , wherein depending on at least one of a type of a road on which the vehicle is running and a region where the road is located, the controller changes the detected distance range defined for each lane mark type, the range being a criterion used to determine the lane mark type by determining whether the detected distance is within the defined range.

7. The image recognition apparatus according to claim 4 , wherein the controller determines the lane mark type as a broken line only when leading ends and/or trailing ends of the lane mark are detected a plurality of times at regular intervals.

8. The image recognition apparatus according to claim 1 , wherein the controller determines the lane mark type as a solid line when the detected distance of the lane mark from the leading end thereof is equal to or greater than a predetermined solid-line detection threshold value.

9. The image recognition apparatus according to claim 1 , wherein the controller determines the lane mark type according to a determination rule defining the detected distance for each lane mark type.

10. The image recognition apparatus according to claim 9 , wherein the determination rule defines an upper limit and a lower limit of the detected distance range for each broken-line lane mark type.

11. The image recognition apparatus according to claim 9 , wherein the determination rule defines the detected distance range for each of a plurality of types of broken-line lane marks that are different in one or both of segment length and segment space.

12. The image recognition apparatus according to claim 9 , wherein the determination rule defines a plurality of detected distance ranges for each lane mark type.

13. The image recognition apparatus according to claim 9 , wherein the determination rule defines a lower limit of the range of the detected distance as measured from a leading end of a lane mark, for a solid-line lane mark type.

14. A navigation apparatus comprising:

an image recognition apparatus according to claim 1 ;

a map database in which map information is stored; and

a executable program embodied on a computer readable medium operable to use the map information and information associated with lane mark type determined by the image recognition apparatus;

wherein the controller executes the executable program to output guidance information.

15. A running lane determination apparatus comprising:

an image recognition apparatus according to claim 1 ;

wherein the image recognition apparatus determines a lane in which a vehicle is running, on the basis of information associated with a lane mark type.

16. A non-transitory computer-readable storage medium storing a computer-executable program usable for image recognition, the program comprising:

instructions for acquiring image information of a plurality of frames of images sensed at predetermined regular time intervals, each image including at least a road surface of an area close to a vehicle;

instructions for performing an image recognition process to detect a leading end and a trailing end of a lane mark included in a detection area defined in each frame of the image information;

instructions for detecting the distance from one of the leading end and the trailing end of the lane mark to the other one as a detected distance on the basis of the speed of the vehicle and the number of frames between a frame in which one of the leading end and the trailing end of the lane mark is detected and a frame in which the other one of the leading end and the trailing end of the lane mark is detected; and

instructions for determining a lane mark type of the lane mark on the basis of the detected distance.