THE FRINGE PROJECTION TECHNIQUE FOR SHAPE ACQUISITION OF LIVE BIOLOGICAL OBJECTS

Profilometry is a technique which measures the shape of a surface. Thi s method provides the height z of every point of a surface above a ref erence plane. A pattern of bright and dark parallel stripes is oblique ly projected onto the object which acts as a screen and the pattern of lines is distorted if the object is not a plane. The distorsion is re lated to the shape of the surface. The presented system uses the spati al phase-stepping technique which allows shape determination from a si ngle video frame, so that it is possible to study a living subject. It is a non-invasive optical technique which allows non-contact measurem ents. As examples, the method is applied to observations of a hand and of a forefinger.