希尔伯特变换结合格雷码的相位展开方法
Phase unwrapping method combining hilbert transform and gray code
夏继隆 1范华 1王晓飞 1张晓磊1
作者信息
- 1. 齐鲁工业大学(山东省科学院)山东省科学院激光研究所,济南 250100
- 折叠
摘要
传统的格雷码辅助四步相移相位展开方法需要投影四幅条纹图形,而且受到环境噪声和投影离焦等因素影响导致重建精度不高.为了提高三维重建的效率和精度,提出了 一种希尔伯特变换与格雷码相结合的相位展开方法.首先,利用采集到的正弦条纹图像和背景光强图像获取余弦分量.然后采用希尔伯特变换将余弦分量与冲击响应进行卷积.在原始频率和幅度保持不变的前提下将相位移动π/2.最后,利用格雷码解码得到的相位级次来求解被测物体的绝对相位.此外,采用三分相位展开法来消除格雷码解相位过程中产生的边缘跳变误差.实验结果表明:该方法在对高精度标准球重建时精度为0.045 mm,重建精度较高.投影条纹图片由四幅缩减到了两幅,提高了投影效率.
Abstract
Traditional Gray-code assisted four-step phase shifting phase unwrapping method requires projection of four stripe patterns,but the reconstruction accuracy is not high due to factors such as environmental noise and defocus-ing of the projector.In order to improve the efficiency and accuracy of three-dimensional reconstruction,a phase un-wrapping method combining Hilbert transform and Gray code is proposed.First,the cosine component is obtained u-sing the acquired sine stripes image and the background light intensity image,and then the cosine component is con-volved with the shock response using the Hilbert transform.Shifting the phase by π/2 while keeping the original fre-quency and amplitude unchanged.Finally,the absolute phase of the measured object is solved by using the phase or-der obtained by Gray code decoding.In addition,the tripartite phase unwrapping method(Tri-PU)is used to elimi-nate the edge hopping error in the process of Gray code phase unwrapping.The experimental results show that the ac-curacy of the proposed method is 0.045 mm in the reconstruction of high precision standard ball,and the reconstruc-tion accuracy is high.The projection stripe images are reduced from four to two,which improves the projection effi-ciency.
关键词
三维重建/结构光/希尔伯特变换/三分相位展开法/格雷码Key words
three-dimensional reconstruction/structured light/hilbert transform/tripartite phase unwrapping method/gray code引用本文复制引用
基金项目
齐鲁工业大学(山东省科学院)科教产融合创新试点工程项目(2022GH003)
齐鲁工业大学(山东省科学院)计算机科学与技术学科基础研究提升项目(2021JC02007)
出版年
2024
NETL
NSTL
万方数据