Patent ID: 8712097

Claim:
An approaching object detection system comprising: a camera which is mounted on a vehicle to capture an image in the vicinity of the vehicle; a processor configured to: perform, on a plurality of continuous images captured in time series by the camera, optical flow processing in which a velocity vector in a certain direction in the images in time series is detected, so that image portions of the images including an object moving in the certain direction is identified; obtain a range of variation in luminance values of pixels of the identified image portions in a direction different from the certain direction and correlate the distributions of the continuous images in time series with each other to compute an enlargement rate of size of the image portions; and determine, by calculating the enlargement rate as the reciprocal of tan(theta) where theta is based on the image portions of consecutive input images, that the object corresponding to the image portions is approaching the camera, when the enlargement rate is increasing.