1. A ranging device utilizing image processing comprising: an image size changing section for obtaining a size-changed image by changing the size of one of two original images captured by a pair of cameras facing forward; a feature extracting section for extracting a feature end points from said size-changed image; a pattern extracting section for extracting a pattern of a prescribed size including said feature end points, and the coordinate of said pattern, from said one of two original images; and a ranging section for searching for the coordinates in the other one of said two images, on the axis on which the coordinate of said pattern exists, to detect the coordinate of a position most correlating with said pattern, and recognizing an object in front of said ranging device to determine the distance to said object based on the difference between the coordinates of the positions in said two original images where said pattern is extracted.