基于Sierra Lite抖动算法的散焦投影光栅测量  

Projector Defocusing Profilometry Based on Sierra Lite Dithering Algorithm

作　　者：吕江昭 达飞鹏[1,2] 郑东亮[1,2] 

机构地区：[1]东南大学自动化学院,江苏南京210096 [2]复杂工程系统测量与控制教育部重点实验室,江苏南京210096

出　　处：《光学学报》2014年第3期127-135,共9页Acta Optica Sinica

基　　金：国家自然科学基金(51175081;61107001);江苏省自然科学基金(BK2010058);中国博士后科学基金(2013M531248)

摘　　要：投影仪散焦技术克服了实时光栅投影三维测量中的投影仪非线性问题,但散焦产生的高次谐波会大大降低散焦光栅的正弦性,带来明显的测量误差。提出了采用"S"形扫描Sierra Lite抖动算法生成二值抖动光栅,较大地改善了散焦后光栅的正弦性,将该抖动技术生成的散焦光栅用于传统的相移算法,基于投影仪散焦投影,得到用于三维测量的绝对相位信息。仿真结果验证了该方法的有效性,改善了散焦光栅的正弦性,提高了相位质量。实际测量实验与仿真结果相一致。与已有的Bayer有序抖动和Floyd-Steinberg抖动生成的光栅相比,所提算法运算速度快,生成光栅正弦性较好,更加适用于散焦投影测量。Projector defocusing technique can eliminate projector nonlinearity in real-time three-dimensional shape measurement. However, the high frequency harmonics brought by defocusing can weaken the sinusoidal feature of the defocused fringe pattern, which can cause obvious measurement error. The Sierra Lite dithering algorithm using a serpentine raster is proposed to generate binary dithered fringe patterns. This method improves the sinusoidality of the defocused fringe pattern. Absolute phase is retrieved by applying fringe patterns generated by this method in traditional phase-shifting algorithm with projector defocusing. Simulations and experiments are carried out to verify the proposed method. Results show that both the sinusoidality of the defocused fringe pattern and phase quality are improved greatly. Compared with the fringes generated by Bayer ordered dithering or Floyd-Steinberg dithering, the proposed method achieves higher performance and can generate fringe patterns more sinusoidally, which is more proper for projector defocusing profilometry.

关 键 词：测量 Sierra Lite抖动算法 光栅投影 散焦 条纹分析 

分 类 号：TP391.4[自动化与计算机技术—计算机应用技术]