A plurality of sets of range data and texture data obtained at different visual points are generated with respect to a measuring object, and relative shift processing of the range data is carried out. At a point to which the range data is shifted, corresponding points of the range data are calculated, and the correlation of the texture data is calculated on the basis of the calculated corresponding points. The minute shift of the range data, the corresponding point calculation processing, and the calculation of the correlation value of the texture data are repeatedly carried out for each minute shift of the range data. The corresponding point for the data exhibiting the highest texture correlation is outputted and the shift quantity of the range data is calculated on the basis of the outputted corresponding point.