用于绝对相位恢复的鲁棒相位编码方法
Robust phase-coding method for absolute phase retrieval
朱浩杰 1汪宇 1梅芳芳 1周传起 1王宇杰 1侯文慧2
作者信息
- 1. 安徽农业大学工学院,安徽合肥 230036
- 2. 安徽农业大学工学院,安徽合肥 230036;安徽省智能农机装备工程实验室,安徽合肥 230036;中科院合肥技术创新工程院,安徽合肥 230036
- 折叠
摘要
相位编码方法已广泛用于条纹投影轮廓术(fringe projection profilometry,FPP)中的绝对相位恢复,然而FPP系统的gamma非线性严重影响了系统的鲁棒性和精度.从扭曲条纹图案中提取的包裹相位将偏离实际相位,不能直接用于恢复绝对相位.为解决这个问题,提出一种基于有效非线性校正策略的鲁棒相位编码方法.首先,通过相位直方图均衡(phase histogram equali-zation,PHE)方法调整失真的包裹相位,以获得校正的包裹相位.理论研究表明,非线性相位误差的频率是理想相位的 3倍,因此提出使用相移直方图均衡(shifted-phase histogram equalization,SHE)方法进一步减小非线性相位误差.然后,通过Hermite插值算法拟合连续函数,减少SHE方法所引入的离散化误差.仿真和实验结果都表明,在gamma非线性情况下,所提方法比传统方法更具鲁棒性.
Abstract
Phase-coding method has been widely used for absolute phase retrieval in fringe projection profilometry(FPP).However,the robustness and the accuracy is severely affected by the gamma nonlinearity of FPP system.The wrapped phase extracted from distorted fringe patterns will deviate from the actual phase,which cannot be directly employed to retrieve the absolute phase.To address this problem,a robust phase-coding method based on an effective nonlinear correction strategy was proposed.First,the distorted wrapped phase could be adjusted by the phase histogram equalization(PHE)method to obtain the corrected wrapped phase.Theoretical studies demonstrated that the frequency of the nonlinear phase error is thrice that of the ideal phase.Therefore,the nonlinear phase error was further reduced by shifted-phase histogram equalization(SHE)method.Then,the continuous function was fitted by the Hermite interpolation algorithm,which could reduce the discretization error introduced by the SHE method.Both the simulation and experimental results show that the proposed method is more robust than the traditional method under gamma nonlinearity.
关键词
条纹投影轮廓术/相位展开/gamma非线性/直方图均衡化/概率分布Key words
fringe projection profilometry/phase unwrapping/gamma nonlinearity/histogram equalization/probability distribution引用本文复制引用
基金项目
安徽省高校科研计划项目(2022AH050872)
电气传动与控制安徽省重点实验室开放基金资助项目(DQKJ202203)
安徽省研究生教育质量工程项目(2022xscx051)
新能源汽车暨智能网联汽车产业技术创新工程项目()
出版年
2024
NETL
NSTL
万方数据