Lane mark recognition device

A vehicle comprising:

• a camera which captures an image of surroundings;
• an edge image generating unit which generates an edge image, into which edge points whose variation in luminance relative to a surrounding portion is equal to or more than a predetermined value have been extracted, from the image captured by the camera;
• a candidate image portion extracting unit which extracts a candidate image portion, which is a candidate for an image portion of a lane mark, from the edge image;
• a lane mark recognizing unit which detects a lane mark candidate based on the candidate image portion and, in a case of having detected at least a pair of lane mark candidates determines whether a distance between the pair of lane mark candidates on the road is equal to or less than a threshold value, and in a case that the distance is equal to or less than a threshold value, calculates a reference value based on a luminance of a corresponding area in the captured image with respect to each of the at least a pair of lane mark candidates and recognizes a lane mark candidate having a maximum reference value as a lane mark;
• and
• a steering control unit which performs steering control of the vehicle so that the vehicle travels within a lane demarcated by the lane mark recognized by the lane mark recognizing unit.

A lane mark recognition method of recognizing a lane mark provided on a road based on an image of surroundings of a vehicle captured by a camera mounted in the vehicle, comprising:

• an edge image generating step of generating an edge image, into which edge points whose variation in luminance relative to a surrounding portion is equal to or more than a predetermined value have been extracted, from the image captured by the camera;
• a candidate image portion extracting step of extracting a candidate image portion, which is a candidate for an image portion of the lane mark, from the edge image;
• a lane mark recognizing step of detecting a lane mark candidate based on the candidate image portion and, in a case of having detected at least a pair of lane mark candidates determining whether a distance between the pair of lane mark candidates on the road is equal to or less than a threshold value, and in a case that the distance is equal to or less than a threshold value, calculating a reference value based on a luminance of a corresponding area in the captured image with respect to each of the at least a pair of lane mark candidates and recognizing a lane mark candidate having a maximum reference value as a lane mark;
• and
• a steering control step which performs steering control of the vehicle so that the vehicle travels within a lane demarcated by the lane mark recognized in the lane mark recognizing step.