Triangulation of surface points with cameras and projectors

Several surface mapping techniques using beam-beam and sheet-beam triangulation with a pattern projector and an electronic camera are presented and compared. The techniques are grouped according the methods they use to circumvent the correspondence problem inherent to optical triangulation systems. These methods are referred to as ´time coding´, ´shape coding´, and ´color coding´. The common term ´coding´ refers to the fact that the correspondence information is coded in a particular fashion for simpler decoding during processing. Also presented is a basic Venn diagram showing the relationship between four typical categories of 3D scene analysis.<>