摘要
格雷码辅助相移技术可以实现具有较强鲁棒性与抗噪能力的三维(3D)形貌测量。为解决由待测物体不均匀的表面反射率、噪声和物体运动等因素造成的级次边沿误码问题,提出了一种基于错位格雷码的动态3D形貌测量方法。将传统格雷码图案在投影前预先移动半个条纹周期得到错位格雷码图案,再采用传统格雷码解码方法对二值化后的错位格雷码图案解码,可得到与截断相位完全错开的解码结果。对该解码结果进行修正后即可利用得到的正确的相位级次辅助截断相位成功展开。同时,为了提高测量精度,引入了一个虚拟相位平面以进一步拓展投影条纹周期数。实验结果表明,所提方法在使用N帧格雷码图案的情况下,可以编码周期数为2;的投影条纹进行3D测量,其无需任何附加图案即可避免级次边沿误码问题,并有效提升了测量精度。复杂动态场景的3D重建结果证明,所提方法能够以2381 frame/s的速率实现高精度、高效率和高速的3D形貌测量。
The Gray-code assisted phase-shifting technique can achieve three-dimensional(3 D) shape measurement with strong robustness and anti-noise ability. To solve the order edge error caused by the uneven surface reflectivity of the measured object, noise, object motion, and other factors, a dynamic 3 D shape measurement method based on misaligned Gray code is proposed. The traditional Gray-code patterns are moved in advance by half fringe period before projection to obtain misaligned Gray-code patterns, then the traditional Gray-code decoding method is used to decode the binarized misaligned Gray-code patterns to acquire a decoding result that is completely staggered from the wrapped phase. By correcting the decoding result, the obtained correct phase order can be used to assist the wrapped phase to be successfully unwrapped. Meanwhile, a virtual phase plane is introduced to further expand the number of projected fringe periods and ultimately to improve the measurement accuracy. The experimental results show that the proposed method can perform 3 D measurement by coding projection fringes with 2;periods when N-frame Gray-code patterns are used, which can avoid the order edge error without any additional patterns and effectively improve the measurement accuracy. The 3 D reconstructed results in complex dynamic scenes prove that the proposed method can achieve high-precision, high-efficiency, and high-speed 3 D shape measurement at a rate of 2381 frames/s.
作者
陆丽莲
吴周杰
张启灿
Lu Lilian;Wu Zhoujie;Zhang Qican(College of Electronics and Information Engineering,Sichuan University,Chengdu,Sichuan 610065,China)
出处
《光学学报》
EI
CAS
CSCD
北大核心
2022年第5期95-104,共10页
Acta Optica Sinica
基金
国家自然科学基金(62075143)
博士后创新人才支持计划(BX2021199)。
关键词
测量
错位格雷码
级次边沿误码
周期数拓展
相位展开
measurement
misaligned Gray code
order edge error
period number expansion
phase unwrapping
