An apparatus for obtaining three-dimensional volume data indicative of the shape of an object by processing the video signal resulting from picking up the object has an image projector for projecting a two-dimensional reference optical image containing a large amount of spatial high-frequency components...http://www.google.com.hk/patents/US5305092?utm_source=gb-gplus-share專利 US5305092 - Apparatus for obtaining three-dimensional volume data of an object
