To make locating and estimating the distance from the camera until the object of interest is still not precise visibility of complicated object in order to be able to know the distance between the object value to the camera.
The location and the approximate distance from the camera to objects that do not accurately see objects that are so complex that they can know the distance between the subject and the camera.
The locating and estimating the distances from the camera to the object interested not in accuracy visible object complex in order to be able to know the distance between the object and the camera.