基于邻接跳变德布鲁因序列的结构光编解码算法  

Structured Light Encoding and Decoding Algorithm Based on Adjacency-Hopping de Bruijn Sequences

作　　者：梁正林 陈彬[1,2] 伍世虔 Liang Zhenglin;Chen Bin;Wu Shiqian(School of Information Science and Engineering,Wuhan University of Science and Technology,Wuhan 430081,Hubei,China;Institute of Robotics and Intelligent Systems,Wuhan University of Science and Technology,Wuhan 430081,Hubei,China)

机构地区：[1]武汉科技大学信息科学与工程学院,湖北武汉430081 [2]武汉科技大学机器人与智能系统研究院,湖北武汉430081

出　　处：《光学学报》2024年第8期74-83,共10页Acta Optica Sinica

摘　　要：德布鲁因序列常被用于结构光条纹的编码,但是序列中相邻的相同码元会导致在相同颜色区域内难以确定码元个数以及每个码元的确切编码范围。为了解决这一问题,提出一种邻接跳变德布鲁因序列,该序列在保留子序列唯一性的基础上保证了相邻码元的相异性。首先,证明了所提出序列的存在性,并给出了其生成方式。然后,将该序列用于相位周期级次编码,结合正弦相移条纹设计了一种彩色条纹编码方法。在解码阶段,按颜色通道分别提取、计算得到包裹相位和相位周期级次,最终获得展开相位。实验结果表明,所提方法与传统相移法有相似的测量精度,且仅需要4幅投影图像即可完成三维测量,显著提高了测量效率。Objective The rapid advancement of modern information technology has led to the increasing maturation of threedimensional(3D) shape measurement technologies.At present,this technology has been applied to biomedicine,cultural relic protection,man-machine interaction,and so on.Structured light measurement emerges as a prominent 3D measurement technology,distinguished by its non-contact,high precision,and rapid speed.It stands as one of the most extensively utilized and reliable 3D measurement technologies.The de Bruijn sequence,noted for the uniqueness of any fixed length subsequence within the entire sequence,is widely employed in structured light coding.In discrete sequence coding,only one projection pattern coded by a de Bruijn sequence is required to measure the 3D information of an object,ensuring high measurement efficiency.In continuous phase-shifting coding,the de Bruijn sequence is applied to code the phase order to assist in the phase unwrapping process.However,the presence of identical consecutive codes in a de Bruijn sequence makes it challenging to precisely determine fringe numbers and positions within uniform color areas in captured images.In this paper,to solve this problem,a new type of de Bruijn sequence named adjacency-hopping de Bruijn sequence is proposed.Such sequences guarantee that all neighboring codes are different while holding the uniqueness of the subsequences.These two properties lay the foundation for accurate decoding and efficient matching.Meanwhile,an efficient and complete structured light coding and decoding process is devised by combining the adjacency-hopping de Bruijn sequence with the phase-shifting method to complete the 3D measurement task.Methods According to graph theory,generating a de Bruijn sequence can be accomplished by systematically traversing an Eulerian tour on a de Bruijn graph.In this paper,we redefine the vertex and edge sets of the de Bruijn graph to construct a specialized oriented graph.This oriented graph ensures that adjacent codes of each vertex are diff

关 键 词：测量 德布鲁因序列 结构光 相移测量 

分 类 号：O436[机械工程—光学工程]