An on-line phase measuring profilometry: Processed modulation using for pixel matching

Abstract An novel on-line phase measuring profilometry (PMP) is proposed, which is more helpful and accurate than the dynamic Fourier-transform profilometry (FTP) in solving the problem where the object motion is along a straight line. It can be used for industrial on-line 3-D shape inspection. In PMP, the phase shifting technique is adopted and the phase calculation from N frames deformed patterns to wrapped phase is a point-to-point performance. The movement of the object results in the displacement of images in deformed pattern, so pixel matching is carried out to modify the positions of images to meet the PMP. Modulation represents the contour of the object, which is used to guide the pixel matching in this paper. Delamination and binarization of the modulation patterns further improve the pixel matching's accuracy and speed. Experiments verify the feasibility and effectiveness of the proposed method.