基于编码结构光的三维成像方法  

3D Imaging Method Based on Encoded Structured Light

作　　者：叶童玲 李锋[1] YE Tongling;LI Feng(Ocean College,Jiangsu University of Science and Technology,Zhenjiang 212114)

机构地区：[1]江苏科技大学海洋学院,镇江212114

出　　处：《计算机与数字工程》2025年第1期240-244,共5页Computer & Digital Engineering

摘　　要：传统结构光三维成像测量技术中所采用的编解码方法大多为二灰度级的格雷码对称结合正弦相移的模式,即设置格雷码的最小编码周期值要等于相移周期值,该方法需投射多幅格雷码图案,且在周期边界处易产生周期错位误差,降低三维测量的精度。为了从根本上解决这一问题,提高三维成像技术的精确度,提出了一种改进的编码方法,即四灰度级的格雷码非对称结合四步相移的结构光编解码成像测量方法,此时相移周期值和格雷码的最小编码周期值并不相同,四灰度级的格雷码的最小编码周期值被设置为四步正弦相移的周期值的一半,由推导的非对称解码原理得到整个测量区域的绝对相位值并根据三角测量原理以及标定结果得到物体的三维坐标,完成整个三维成像的过程。3dmax仿真测试结果和实物测试结果表明:与传统二灰度的格雷码-相移技术相比,四灰度级的格雷码图案的使用在减少了投射图案的数目的同时具有抗干扰能力,非对称结合模式的编解码技术有效地消除了周期错位,测量精度大大提高。Most of the encoding and decoding methods used in the traditional structured light 3D imaging measurement tech⁃nology are two-gray-level gray code symmetrically combined with sinusoidal phase shift,that is,the minimum encoding period of the gray code is set equal to the phase shift period,and this method needs to project multiple gray code pattern,and the periodic dis⁃location error is prone to occur at the periodic boundary,which reduces the accuracy of the three-dimensional measurement.In or⁃der to fundamentally solve this problem and improve the accuracy of 3D imaging technology,an improved coding method is pro⁃posed,which is a four-gray-level gray code asymmetry combined with a four-step phase shift structured light coding and decoding imaging measurement method.The minimum coding period of the gray code is not the same as the phase shift period.The minimum coding period of the gray code with four gray levels is set to be half of the period of the four-step sinusoidal phase shift.The absolute phase value and the 3D coordinates of the object are obtained according to the calibration results and the principle of triangulation,thus complete the entire 3D imaging process.The 3dmax simulation test results and physical test results show that compared with the traditional two-gray-level gray code-phase shift technology,the use of four-gray-level gray code reduces the number of projected patterns and has anti-interference ability,asymmetrical the combined codec technology effectively eliminates the period disloca⁃tion,and the measurement accuracy is greatly improved.

关 键 词：结构光 三维成像 编解码模式 四灰度格雷码 四步相移 非对称结合 相位展开 

分 类 号：TP391.4[自动化与计算机技术—计算机应用技术]