3-DIMENSIONAL GAUGING BY ELECTRONIC MOIRE CONTOURING

Three-dimensional gauging involves the measurement and mapping of thre e-dimensional surfaces. Gauging accuracy depends on measurement accura cy in the images, image scale, and stereo-geometry. In industrial appl ications such as for quality control, multiple cameras are often neede d to provide adequate stereoscopic coverage of the object. This paper reports an opto-electronic technique for obtain shape gauging from a d iffuse object using just one camera. The surface to be measured is mod ulated by a linear fringe pattern that is projected using a convention al slide projector. In order to obtain a contour map of the surface, d emodulation is carried out electronically producing a moire pattern. D igital image processing by a computer, linked to the opto-electronic d evice is employed to determine the surface shape.