Measurement of Three Dimensional Objects Using Gray Code Projection

This paper describes a novel three dimensional measuring system using gray code projection. The method of this system is based on the principle of time sequential space encoding. Measurement space is encoded to 256 spaces by four gray level patterns, and it takes about 0.6 second that we get this encoded image. These patterns are projected by liquid crystal color projector, and are taken by CCD camera. When measurement area is 120mm×100mm, measurement accuracy of this system is 1mm, and the standard deviation is 0.4mm in the horizontal crosssection, 0.24mm in the vertical cross-section.