1. A method of controlling a stereo convergence, the method comprising: storing a setup specification information according to preferences of a user, the setup specification information including a plurality of distance ranges; detecting a plurality of objects from a stereo image comprising a left eye image and a right eye image; grouping the plurality of objects into a plurality of object groups according to the setup specification information, each of the plurality of object groups corresponding to a different one of the plurality of distance ranges; selecting one of the plurality of object groups as a selected object group based on the plurality of distance ranges indicated by the setup specification information; and moving at least one of the left eye image and the right eye image of the stereo image to adjust convergence of the selected object group or to adjust convergence of a setup area comprising the selected object group in a horizontal direction or a vertical direction, or in both the horizontal direction and the vertical direction, wherein the plurality of objects are grouped based on distances between an imaging surface of a camera and the plurality of objects.