Applying innovative stripes adaptive detection to three-dimensional measurement of color fringe profilometry

This study developed a 3D software and hardware measurement system, and proposes an innovative stripes adaptive detection algorithm. The fringe intensity is regulated automatically according to the reflection coefficient of different analytes, in order to avoid overexposure. For the measurement of the object in discontinuously changing height, a novel intensity difference coding unwrapping phase technology is used, thus overcoming the technological bottleneck of traditional phase unwrapping. In order to increase the measurement efficiency, the stripe pattern is combined with intensity coding pattern by three-channel color information, in order to generate an adaptive compound color stripe pattern. The measurement efficiency is increased by approximately two times compared with traditional gray stripe pattern. In order to increase the measurement accuracy, the uneven brightness is corrected by using brightness gain function. The three-channel intensity nonlinear response is corrected by cubic spline interpolation system response inverse function. The three-channel image is corrected by color cross-talk correction technology. The experiment proved that the system repeatability is 20 µm. The traditional phase-shifting profilometry is improved successfully, overcoming the technical measurement bottleneck of discontinuous change in the analyte height, so as to attain low cost, high measurement accuracy, efficiency and measurement reliability.