基于数字近景立体摄影的三维表面模型构建

3D Surface Model Constructing Based on Digital Close-Range Stereo Photography

采用经过标定的数字近景立体摄影系统Z-System获取待建模对象的数字立体像对序列,探讨利用这些立体像对进行三维表面构建的方法。在构建三维目标表面模型时,首先根据数字近景立体摄影测量原理,提取目标表面的特征点和计算特征点的三维坐标;然后利用各立体像对内特征点的像平面坐标,按二维空间TIN(tri-angulated irregular network)构建方法得到离散特征点在三维空间中的拓扑连接关系,进而构建单像对内目标的局部表面TIN模型;最后再利用序列像对间的公共连接点,进行坐标转换,从而在三维空间中将各单立体像对的表面模型拼接成一个完整的三维表面模型。实验结果表明,该方法具有快速灵活的特点且行之有效。

Stereo image pair sequences of the object are obtained by the calibrated digital closerange stereo photography system Z-System. This paper discusses the method of 3D surface model constructing for stereo images. In this method, feature points of the object and their 3D coordinates are firstly obtained by the theory of digital close-range stereo photogrammetry. Secondly, according to pixel coordinates of feature points in each stereo image pair, their topology connecting relations in 3D space are directly constructed by the method of 2D TIN （triangu lated irregular network）construction. Therefore, 3D TIN model of the partial object is obtained based on these topology connecting relations. Finally the coordinate transformation is carried out by common points among stereo image pair sequences, thus a whole 3D surface model is constructed by connecting all partial surface TIN models in 3D space. The experimental result shows that the method is fast, flexible and effective.