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Physical Sciences and Mathematics Commons

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Selected Works

Dr Yanguang Yu

Profilometry

Articles 1 - 3 of 3

Full-Text Articles in Physical Sciences and Mathematics

A New Phase Unwrapping Algorithm Based On Three Wavelength Phase Shift Profilometry Method, Limei Song, Xiaoxiao Dong, Jiangtao Xi, Yanguang Yu, Chaokui Yang Dec 2012

A New Phase Unwrapping Algorithm Based On Three Wavelength Phase Shift Profilometry Method, Limei Song, Xiaoxiao Dong, Jiangtao Xi, Yanguang Yu, Chaokui Yang

Dr Yanguang Yu

Phase Shift Profilometry (PSP) method is widely used in 3D shape measurement. The advantage of the PSP method is that it is less sensitive to the surface reflectivity variations and the object can be measured point by point. But if only a single wavelength λ1 is used, the step height cannot be larger than λ1/4. In order to measure step height object, Gray Code (GC) and Multi-Wavelength Phase Shift Profilometry (MWPSP) method are used. But the GC method cannot solve the problem of the objects with a variety of colors under different illumination. The shortcoming of MWPSP …


Partially Overlapped Range Images Registration Based On Fringe Pattern Profilometry, Xiaochen He, Jiangtao Xi, Yanguang Yu Dec 2012

Partially Overlapped Range Images Registration Based On Fringe Pattern Profilometry, Xiaochen He, Jiangtao Xi, Yanguang Yu

Dr Yanguang Yu

Registration of two three-dimensional (3-D) point sets is a fundamental problem of 3-D shape measurement and modeling pipeline. This paper investigates the automatic pair-wise method to register partially overlapped range images generated by self-developed fringe pattern profilometry (FPP) system. The method is based on the classic iterative closest point (ICP) algorithm but combined with several extensions to adapt to the experimental data. Firstly, the distance function for correspondence finding is modified to be the weighted linear combination of positions and Euclidean invariant features for improving the probability of convergence. In addition, outliers can be discarded through robust statistics and adaptive …


Fast Quality-Guided Phase Unwrapping Algorithm For 3d Profilometry Based On Object Image Edge Detection, Ke Chen, Jiangtao Xi, Yanguang Yu Dec 2012

Fast Quality-Guided Phase Unwrapping Algorithm For 3d Profilometry Based On Object Image Edge Detection, Ke Chen, Jiangtao Xi, Yanguang Yu

Dr Yanguang Yu

A main challenge associated with 3-dimentional fringe pattern profilometry (3D-FPP) systems is the unwrapping of phase maps resulted from complex object surface shapes with both robustness and speed guaranteed. In this paper we propose a new quality-guided phase unwrapping algorithm. In contrast to the conventional quality-guided methods, we classify pixels on wrapped phase map into two types by detecting edge pixels on object image: high quality (HQ) pixels corresponding to smooth phase changes and low quality (LQ) ones to rough phase changes. In order to improve the computational efficiency, these two types of pixels are unwrapped by means of different …