A stereo image device includes a representative point selection unit for selecting a plurality of representative points in a first image of a stereo-pair image; a corresponding point control unit detecting a plurality of corresponding points corresponding to the plurality of representative points in a second image of the stereo-pair image and excluding any corresponding point(s) judged to be a deviating point; a deviation value calculation unit for judging whether corresponding points are the deviating points or not; an approximation curve calculation unit performing a curve approximation on all the corresponding points except the excluded corresponding points; a height correction value calculation unit calculating a height correction value from a plurality of approximation curves drawn up by the curve approximation; a parallelization execution unit performing parallelization of the second image on the basis of the height correction value.