Color-coded projection grating method for shape measurement with a single exposure

Appl Opt. 2000 Jul 10;39(20):3504-8. doi: 10.1364/ao.39.003504.

Abstract

A fast and efficient technique for profilometric measurement with a color-coded grating is proposed. Eight colors are used to code the grating, and each color represents only one logical state. There are 64 stripes in one period of the color grating, which is large enough for normal measurement. Compared with the previous techniques, it has the advantages of simple hardware without moving mechanical parts, single exposure for obtaining three-dimensional information, little influence from noise and from nonlinearity of the CCD camera on the measurement accuracy, and higher anti-color-blurring capability. The suggested technique is suitable for on-line inspection and dynamic measurement of moving objects.