Large-area Measurement with Stereo Deflectometry

Stereo deflectometry can specify the position of workpiece and reduce the difficulty of geometrical calibration. But the measuring scope is limited, and this issue is especially severe for the measurement of complex surfaces. A method is proposed to extend the measuring scope of stereo deflectometry. The nominal model of the surface under test is aligned with the overlapped measurement area of the stereo system, and the other areas are measured using the monoscopic SCOTS approach. This method effectively combines the advantages of stereo and monoscopic deflectometry, and the measuring accuracy and flexibility can be guaranteed. © 2020 The Author(s)