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Proceedings Paper

Selection of phase-recovery algorithms for fringe processing in optical measurement of micro-surface
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Paper Abstract

Success of optical measurement methods such as interferometry, holography and fringe projection methods mainly depends on the availability of robust phase recovery (PR) algorithms. In presence of some problems such as strong noise, abrupt phase changes, low fringe contrast and discontinuities, it’s necessary to introduce a highly reliable algorithm to overcome them. As for the experimental phase map from holographic interferometry of China coin’s micro-surface, some typical PR algorithms including the proposed (weighted) DCT (Discrete Cosine Transform) are studied to try to recover the satisfactory continuous phase. The experimental phase map (13921040 pixels) exhibits the local surface characteristic of one China coin. It features excessive noise and many bad data points. It’s very difficult to achieve the continuous phase by the general algorithms. So some robust algorithms are studied to solve this problem. These algorithms include the quality map guided method (QG), (weighted) least square method (LS or WLS), mask cut method (MC) and (weight) DCT method (DCT or WDCT). According to the tested results, the fastest algorithm is the LS method, and it only needs about 10s. The clearest pattern profile results from the DCT and WDCT algorithms that need about 30s and 31s in the consuming time, respectively. However, it’s very hard to clearly and completely reflect the smooth top of imprinted letters for all the above algorithms. This could be due to the excessively much noise, the limited resolutions of CCD setup, and so on.

Paper Details

Date Published: 13 September 2012
PDF: 7 pages
Proc. SPIE 8493, Interferometry XVI: Techniques and Analysis, 84931B (13 September 2012); doi: 10.1117/12.927783
Show Author Affiliations
Yongjian Zhu, Zhejiang Univ. of Science and Technology (China)
Jilin Univ. (China)
Weiqing Pan, Zhejiang Univ. of Science and Technology (China)
Anhu Li, Tongji Univ. (China)
Yanan Zhi, Shanghai Institute of Optics & Fine Mechanics (China)


Published in SPIE Proceedings Vol. 8493:
Interferometry XVI: Techniques and Analysis
Joanna Schmit; Katherine Creath; Catherine E. Towers; Jan Burke, Editor(s)

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