Review of fringe-projection profilometry and phase measuring deflectometry

Fringe-projection profilometry and phase measuring deflectometry can realize high accurate measurement of three-dimensional shape, which has good development prospect in the full field threedimensional profilometry. First, the measuring principles of fringe-projection profilometry and phase measuring deflectometry were introduced. Moreover, the technologies of phase extracting and camera calibration in fringe-projection profilometry and phase measuring deflectometry were also especially emphasized, which were key technologies. Then the similarities and differences of fringe-projection profilometry and phase measuring deflectometry were compared. What's more, the development direction and problems to be solved of enhancing the measurement accuracy and speed in fringe-projection profilometry and phase measuring deflectometry were introduced. In order to improve the measurement accuracy, main methods can be divided as follows: correcting the the Gamma effect of a digital projector and a digital camera, improving the phase extraction accuracy of the fringes, enhancing the camera calibration accuracy, phase-height/gradient calibration accuracy and other means. In order to improve the measurement speed, the phase extraction speed and the phase unwrapping speed were improved.