基于四目系统的真实场景三维建模

Real scene 3D modelling based on four-camera vision system

为实现敦煌莫高窟文化遗产数字化保护,设计了一套基于四目系统的真实场景三维建模方法。针对双目立体视觉系统特征点匹配精度不高的问题,构建了一种四目立体视觉系统,并设计了与之相适应的高精度立体匹配策略,运用四目系统的冗余设计和自检验功能,可以获得高精度的空间点云数据。针对Delaunay三角化结果中不相关目标的错误连接问题,增加三角形边长分别在图像坐标系和世界坐标系中的约束条件,抑制错误三角形,该条件可根据点云数据分布特征自适应获取。该系统已被运用到莫高窟第172窟的三维重建中。结果表明:该系统可以重建多目标、深度变化大的复杂场景,172窟的有效点云为41 649点,三维建模时间约为0.5h。

In order to realize the cultural heritage digital protection of Mogao Grottoes in Dunhuang, a real scene 3D modeling method based on the four-camera vision system was designed. At first, aiming at the problem of low accuracy of the feature points matching in binocular ster- eo vision system, a four-camera stereo vision system and high-accuracy stereo matching strate- gy adapted to it were designed. Using the redundant design and self-checking function of the four-camera vision system, the high-accuracy spatial point cloud data can be obtained. Then, aiming at the problem of error connection between the uncorrelated objects in the Delaunay tri- angulation results, the length of triangle constraint condition in the image coordinate system and the world coordinate system were increased. It can be used to prevent the error triangle. The condition can be obtained adaptively according to the point cloud data distribution characteristic. The system has been applied to the 3D reconstruction of the 172nd cave in Mogao Grottoes. The results show that the system can reconstruct the complex scenes with multiple objects and large depth changes efficiently. The 172nd cave has 41649 effective point clouds, and the 3D modeling time is about half an hour.