This paper considers the problem of how to use a camera to recognize the shape of a path without using too much image processing time. A quadrangle image scene is divided into three parts, and the center of gravity of an object in each part is extracted to estimate the shape of the path. A strategy for how to measure distances with a camera is also presented. The idea behind this strategy is first to establish a methematical model describing the relationship between pixel distance in the image scene and real distance in front of the mobile vehicle by experiments, and then to decide the relevant position of the object by means of rotation of the camera. These image processing methods can be used in control problems with mobile vehicles/car-like robots, and can be used in fuzzy control, neural control, and other control strategies.