A novel and fast three-dimensional measurement technology for the objects surface with non-uniform reflection

Abstract

Optical three-dimensional (3D) measurement of non-diffuse objects is challenging. At present, a common used method is to adjust the camera’s sensitivity several times to get fringe sequences with different brightness, and then extract the appropriate pixels for 3D shape reconstruction. However, the disadvantages of this method are obvious, including the large number of fringes needed, many useless redundant images, large amount of computation and time-consuming. In this paper, a novel method is proposed, which includes four major steps. Firstly, we set the intensity of the projected fringes to be maximum to ensure that the captured fringes have a good signal-to-noise ratio (SNR). Secondly, two sets of additional fringes are pre-captured to estimate the reasonable exposure time interval. Thirdly, appropriate exposure time is selected and the high-speed projection technology is used. Finally, appropriate pixels are extracted from the fringe sequences for 3D reconstruction, and then multiple phases are calculated and fused. Compared with the existing methods, the proposed method does not capture useless fringe patterns, and greatly improves the measurement efficiency while guaranteeing satisfactory 3D measurement results.