【作者】 程莹；

【导师】 张剑清；

【作者基本信息】 武汉大学 ， 摄影测量与遥感， 2005， 硕士

【摘要】 近景摄影测量作为摄影测量的一个重要分支,近一、二十年以来获得了很大的发展。在当今的信息时代,近景摄影可作为快速采集各种信息的一种最有效的手段,为信息系统提供必要的基础数据。在零件制造,建筑物立面测量,地质、考古、医学整形,交通事故快速处理等领域有着广泛的应用前景。然而相当数量的工业机械目标和生物医学目标表面缺乏纹理。对于这些纹理贫乏的目标采用基于结构光得重建方案。将特定光条投影到被测物表面,在被摄目标表面形成可用于匹配的结构光纹理。结构光的种类可分为点、平面、网格状等类型。 本文以摄影测量的基本原理和理论为基础,利用基于结构光的三维重建方法,通过计算得到纹理贫乏目标(石膏像)的表面模型。被摄目标表面缺乏纹理信息,无法用一般的立体影像匹配方法进行匹配。为了解决特征点的匹配问题,本文提出一种基于结构光的三维重建方法:利用激光器投射到石膏像表面的结构光作为用于匹配的纹理。保持物体不动和激光器投射方向不变,交向拍摄两幅影像,构成一个立体像对。保持被摄物体位置不改变,通过改变激光器的投射方向,在物体表面不同位置得到一系列特征曲线纹理的同时也得到一组连续像对。每个单独的像对中,利用相对定向直接解的方法恢复拍摄时立体像对的两幅影像的相对方位,从而确定同名核线。同名核线与该像对中特征曲线纹理的交点即为一对同名点。经前方交会得到该特征曲线上点的三维模型坐标。利用独立模型法进行模型连接,将所有特征线曲线的模型坐标归算到统一的模型坐标下,得到石膏像表面“点云”的三维模型坐标。 采取分块构网以保证每块的所有空间点可以无重叠的投影到二维平面上。保持点的连接关系不变,从而得到空间点的三角网模型。最后,建立每个模型点坐标(X,Y,Z)与影像坐标(x,y)之间的映射关系,将影像纹理映射到数字表面模型上并利用OPENGL技术显示石膏像完整的三维数字表面模型。更多还原

【Abstract】 Close Range Photogrammetry, which is a branch of photogrammetry, has development rapidly in the past twenty years. Nowadays, Close range photogrammetry is an effective way been used to gather different information as essential basic data for information system. It has an extensive application prospect in archaeological studies, medical science, the traffic accident deal with fast etc. We use a method for 3D-Reconstruction based on structure lighting, this method is applicable for the object with indigent texture such as some industry goals and biomedical goals that is used for matching. The structure lighting, which is projected on the object by laser, is used as the texture for matching. This texture includes point, pain, grid chart etc.Because the surface of the plaster model is absent of the texture, we are difficult to match the corresponding points. This paper introduces a method based on structured light to find correspondent points on the Epipolar Lines and the laser feature lines. The method resolves the difficulty of the matching of the corresponding identical points, and it’s easy to be carried out and requires low hardware. So the method the paper protests can be popularized in the 3D Reconstruction of the objects with indigent texture or in the condition of bad illumination.Keep the objects not moving, by changing the direction of the laser projection, we can get a series of curve texture on the object. By changing the direction of laser to projected different texture on the object. For the purpose of 3D-reconstruct the object, we can get corresponding point in each corresponding curve by using the method of relativity direct solution. After The forward intersection we can get the coordinate of the point which is on the surface of plaster model. When we use this point to generate TIN, we must project the spatial points to the plane and every point can’t overlap each other. So we also must generate TIN patches dividually then merge them into the whole plaster model’s DSM.更多还原