| 摘要 |
PROBLEM TO BE SOLVED: To suitably monitor a vehicle or the like approaching one's own vehicle. SOLUTION: A differential value of the concentration of each pixel of an omnidirectional image by an omnidirectional visual sensor is calculated by a projection part; a concentration differential image is led out and an annular watching region is set in it; an annular edge histogram is formed by calculating a concentration projection value that is an added sum of concentration in the radiation direction in the watching region by the projection part; a time series image expressing the temporal variation of the concentration projection value is formed by developing the edge histogram into a band-like form by a binarization part with the six-o'clock direction as a reference position; a binarization image is formed by binarizing the time series image by a predetermined reference concentration threshold value; whether a region having higher concentration than the reference concentration threshold value whose width continuously and gradually increases in terms of time is present or not in the binarization image is determined by a determination part; and when it is present, the high concentration region is recognized as an obstacle approaching the one's own vehicle from the rear. |
