High precision computer-generated moiré profilometry

Abstract

Recently, a computer-generated moiré profilometry was proposed by our research group. It can effectively avoid the influence of the transient caused by moiré fringes’ direct acquisition and generally owns a higher accuracy. But when the spatial spectrum of the captured deformed pattern is severely aliased caused by the measured object, the accuracy of this method may be affected to some extent due to the impure background light component extraction. So, a high precision computer-generated moiré profilometry based on background light component’s accurate elimination is proposed. By adding an additional special phase-shifting sinusoidal grating to accurately extract valid information in the spatial domain and improve the sinusoidal feature of the pattern, the measurement precision can be improved effectively. Though the single-shot feature is broken, the real-time measuring feature is still maintained successfully. Experimental results show the feasibility and validity of the proposed method.

Fiber-Based High-Speed Fringe Projection Profilometry

“…A method known as modulation measuring profilometry [13] uses a crossed grating and the where the vertical and horizontal components are separated in image space. Another technique uses the Moiré principle, where a grating is placed in front of the light source and the camera, these overlapping gratings are used to do Moiré profilometry [14], gratings can also be created through digital projection [15].…”

Colored digital Moire technique for self-occluding shading in fringe projection profilometry

“…12,21 Several approaches employ the projected phase carrier to calculate the moiré pattern by arithmetic and algebraic manipulation so that the extracted phase quality is comparable to that using PSAs. 22,23 Digital moiré's advantages underlie the high speed and simplicity, whereas the approach to calculate the moiré pattern drives the accuracy of the technique. We highlight that one should not consider digital moiré as a spatial phase carrier method even though it phase demodulates the fringe signal using the carrier as a reference; the reason is that this technique aims to estimate an input signal for a PSA.…”

Application of Moire Profilometry in Three-Dimensional Profile Reconstruction of Key Parts in Railway

“…This method could avoid color or texture interference and has higher measurement accuracy than FTP [ 14 ]. He also proposed a high-precision computer generated MP, based on accurate elimination of background light components [ 15 ]. Tang et al proposed a phase compensation method to solve the problem of 2π ambiguity in moire projection method [ 16 ].…”