1. A method for associating a stereo image, by acquiring images of an object from a first point and a second point and by associating the image at the first point and the image of the second point, comprising a step of moving from the first point to the second point while taking an image of the object with an image pickup device, a step of setting two or more pass points on the image of the first point, a step of setting a retrieval range with the pass point as a center, a step of comparing a preceding image and a subsequent image over time, a step of retrieving the pass points of the preceding image within said retrieval range and identifying the pass points of the preceding image in the subsequent image, a step of retrieving and identifying the pass points sequentially with respect to every frame image data from the image of the first point to the image of the second point, a step of identifying the pass points of the image of the second point, a step of performing a relative orientation of the image at the first point and the images at the second point based on the pass points of the image at the first point and the pass points of the image at the second point, and calculating a tilting of the images and a magnification factor of the images and a step of correcting a deviation of first image data from second image data based on the tilting and the magnification factor thus calculated.