1. A stereo matching apparatus, the apparatus comprising: an extractor configured to extract a scan line relevant to a corresponding point in a stereo image; a first determiner configured to determine a cost at a node of a plurality of stages relative to an image of a current scan line depending on from which level among a same level, an upper level and a lower level of a previous stage a cost of same stage of an upper scan line is determined, and whether a cost of the same stage of the upper scan line is determined by other disparities; a designator configured to designate a path in response to the determined cost; and a second determiner configured to determine a path that minimizes energy at the designated path.