By overlaying images taken from two different angles, it is possible to differentiate altitudes of the topography, and then produce a "digital topographical model." From this, contoured images giving the impression of three dimensions can be produced.
如果把兩張從不同角度拍攝的影像疊合在一起，可以算出地形的高低起伏，做出「數值地形模型」，還可以進一步做出透視的立體影像。