1. A coordinate calculating apparatus for calculating two object position coordinate points from an image captured by an image capturing apparatus, the two object position coordinate points indicating positions of two predetermined objects whose images are captured, such positions being indicated on a plane corresponding to a plane of the captured image, the apparatus comprising: coordinate detecting programmed logic circuitry configured to detect a position coordinate point for each area satisfying a predetermined condition in the captured image; vector setting programmed logic circuitry configured to set a vector indicating a relative positional relationship between two position coordinate points in the captured image; and coordinate determining programmed logic circuitry configured to determine one of the detected position coordinate points detected by the coordinate detecting programmed logic circuitry as one of the object position coordinate points, and determining the other object position coordinate point using the one of the detected position coordinate points and the vector.