| Optical 3-D profilometry is used widely for industry measurement, machine vision, profile modeling, shoemaking engineer, biomedical industry, etc. Fourier Transformation Profilometry (FTP) based on fringe projection is one of an important 3-D sensing method, including following merits: only one fringe needed, full field analysis, and high precision. With the development of computer hardware and software technique and high-resolution image grabber, FTP has become one of the most important and popular methods and payed more and more researchers' attention.Based on the discrete Fourier transform analytical method, this paper discusses the influence of the pixel size of CCD and proposes a new filtering method. The main results can be summarized as following:1 Aimed at the problems existed in the study of influence of sampling in FTP, we discuss the first sampling when CCD captures the information of object., and discuss the influence of the pixel size of CCD, such as the limitation of bandwidth and the frequency overlapping. Now we discuss the sampling model of CCD and give the expression and sampling selection criteria. The discussion makes the research of sampling theory in FTP more actually and practically.2 Filtering is an important process in Fourier transform profilometry, and it is also an important factor for influencing precision. In this paper, a new filtering method is proposed, which is an efficient method to improve the measuring precision. This method can keep enough frequency and eliminate the random noise,and there is no need to choose a filtering window. |
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