PARALLEL 3-DIMENSIONAL SENSING BY COLOR-CODED TRIANGULATION

We discuss a three-dimensional sensor that combines coded illumination and triangulation. The sensor supplies the distance of approximately 250,000 object pixels (TV format) in 40 ms (one single TV frame period ). The method is based on the following principle: a color spectrum of a white-light source is imaged onto the object by illumination from o ne certain direction. The object is observed by a color TV camera from a direction of observation, which is different from the direction of illumination. The color (hue) of each pixel is a measure of its distan ce from a reference plane. It can be evaluated by the three (red-green -blue) output channels of the CCD camera. This evaluation can be imple mented within TV real time. Even colored objects can be measured. The resolution achieved is 50-150 depth steps.