NEW CONCEPT OF A PHOTOGRAMMETRY SYSTEM WITH ADAPTED 'INTELLIGENT' ILLUMINATION FOR 3D-SHAPE CAPTURE USING COMPUTER GENERATED HOLOGRAMMS

摘要

A non-contact measurement system, based on the principle of photogrammetry, developed at the Fraunhofer IPT, permits a highly exact 3D-shape-measurement of objects. Because of the limited depth focus of the projection lens used, the axial measurement range is reduced to only a few centimetres. In order to digitize the 3D-shape of technical objects of various dimensions, the structured illumination on the object surface must be in focus for each axial depth. The principle of holographic projection offers a crucial benefit, in order to project a sharp pattern in any plane. By applying computer generated holograms for projection of patterns, further depth information can be encoded. Only this allows the measuring of 3D-shapes in one step.