基于条纹投影三目系统的舌面完整点云获取方法

A method for obtaining complete point cloud of tongue surface based on fringe projection trinocular system

传统的舌诊过程存在客观性较差的问题,将计算机视觉技术应用于舌诊可以有效推进舌诊客观化。双目立体视觉结合结构光条纹投影技术是三维测量的常用手段,但对于舌诊的测量场景,由于舌体表面常带有津液和口水等,造成条纹图像出现分布随机性较大的高反光区域,导致相位解算错误和点云缺失。本文提出了一种基于光栅投影的三目测量系统,由3个相机构成1个三目和3个双目子系统。在相位和级次约束基础上引入双极线约束,提高三目立体匹配精度,并利用匹配点补充优化三目匹配点集,重建高反光区域点云。结果显示,对比传统双目系统,本系统的匹配精度和重建精度均得到提升,特别是在真实舌面测量中能够生成纹理清晰、特征完整的点云,对舌面高反光区域进行了有效测量,有助于舌诊的客观化进行。

The traditional tongue diagnosis process has the problem of poor objectivity.Applying computer vision technology to tongue diagnosis can effectively promote its objectivity.Binocular stereo vision combined with structured light fringe projection technology is a common method for 3D measurement.However,in the measurement scenario of tongue diagnosis,due to the presence of saliva and fluids on the tongue surface,there are high-reflectance areas with significant random distribution in the fringe images,leading to errors in phase calculation and point cloud loss.A trinocular measurement system was proposed based on fringe projection,where a trinocular system and three binocular subsystems were composed of three cameras.Dual-epipolar constraint based on phase and order constraints was introduced to enhance the accuracy of trinocular stereo matching.Supplementary matching points were utilized to optimize the trinocular matching point sets,reconstructing point clouds in high-reflectance areas.The results indicated that,compared to traditional binocular systems,this system achieved improved matching and reconstruction accuracy.Particularly in real tongue surface measurements,it could generate point clouds with clear textures and complete features.It could effectively measure the highly reflective area of the tongue surface and facilitate objective tongue diagnosis.