Wang Yongchang, Liu Kai, Lau Daniel L, Hao Qi, Hassebrook Laurence G
Center for Visualization and Virtual Environments, University of Kentucky, Lexington, Kentucky 40507, USA.
J Opt Soc Am A Opt Image Sci Vis. 2010 Sep 1;27(9):1962-71. doi: 10.1364/JOSAA.27.001962.
Structured light illumination by means of phase shifting patterns is a widely employed method for three-dimensional (3-D) image acquisition that is robust to ambient light and object albedo but may be especially susceptible to sensor and environment noise. In this paper, we study the specific technique of phase measuring profilometry (PMP) and the maximization of a pattern's signal to noise ratio (SNR). By treating the design of an N-pattern PMP process as placing points in an N-dimensional coding space, we define a pattern's SNR in terms of a pattern set's computational length and the number of coded phase periods in the projected patterns. Then, without introducing phase ambiguities, we propose a so-called edge pattern strategy that maximizes the computational length and number of periods. Theoretically, the edge pattern technique improves the SNR by 1.2381 times when using three component patterns and by 15.5421 times when using five patterns. Experimental results further demonstrate the improved SNR of the proposed edge pattern technique such that more accurate 3-D results are achieved using fewer component patterns.
通过相移图案进行结构光照明是一种广泛应用于三维（3-D）图像采集的方法，该方法对环境光和物体反照率具有鲁棒性，但可能对传感器和环境噪声特别敏感。在本文中，我们研究了相位测量轮廓术（PMP）的具体技术以及图案信噪比（SNR）的最大化。通过将N图案PMP过程的设计视为在N维编码空间中放置点，我们根据图案集的计算长度和投影图案中编码相位周期的数量来定义图案的SNR。然后，在不引入相位模糊的情况下，我们提出了一种所谓的边缘图案策略，该策略可最大化计算长度和周期数。理论上，当使用三个分量图案时，边缘图案技术可将SNR提高1.2381倍，当使用五个图案时，可提高15.5421倍。实验结果进一步证明了所提出的边缘图案技术提高了SNR，从而使用更少的分量图案就能获得更准确的3-D结果。
