Portal de Periódicos da CAPES

<title>Structured light measurement by double-scan technique</title>

1996; SPIE; Volume: 2784; Linguagem: Inglês

10.1117/12.248527

1996-756X

Hansjoerg Gaertner, Peter Lehle, Hans J. Tiziani, Christoph Voland,

Advanced Optical Sensing Technologies

3D-measurement systems, that are based on triangulation, like light sectioning, structured light or stereo vision have a common problem. Certain areas of the object surface are not illuminated and others cannot be seen. In these regions no range data can be acquired and the resulting range map is incomplete. A new measurement setup with structured light is presented reducing this shadow/occlusion problem for many surfaces. For structured light measurement systems several patterns are projected onto the object to be measured. A CCD-camera acquired the images of the object illuminated with structured light patterns. For each pixel of the CCD-matrix there is a sequence of gray-values that corresponds to a light plane of the projector. The position of the pixel in the CCD-matrix determines a viewing beam. The intersection point of the viewing beam and the plane of light yields the three coordinates of a surface point of the object. In the new setup a pattern projector is used together with a camera. With a beam splitter, two color filters and mirrors two beams of different color and different angle of incidence are obtained. Thus, two colored patterns superimpose on the object. A color CCD-camera acquires the image for the range data measurement. Two of the three color channels detect the projection pattern of the corresponding color. A range data image is calculated from the two measurements. A nearly complete range data image result with no or only a few regions without range information.