像控后处理倾斜摄影三维建模方法研究

Three-dimensional modeling of oblique photographywith post-processed image control

无人机倾斜摄影三维模型的精度是衡量模型质量好坏的重要指标.常规的倾斜摄影三维建模需要先布设像控点,作业效率低且维护成本高.无像控建模不需要布设像控点,航测效率高,但精度较低.本文以南京信息工程大学东苑为实验区,研究了一种像控后处理倾斜摄影三维建模方法.结果表明:1)基于像控后处理建立的三维模型与常规方法建立的三维模型精度基本相同,平面中误差、高程中误差均小于0.05 m,满足高效率、高精度、低成本的建模要求;2)像控后处理建模避免了制作和维护像控点的过程,同时基于已有高精度三维模型选择像控点并提取坐标,提升了像控点选择的科学性并降低了外业测点的工作量;3)该方法在城市、乡镇及其他道路丰富地区高精度三维实景模型定期更新上具有较好的普适性.

Accuracy is an important indicator of the three-dimensional(3D)model of UAV oblique photography.Conventional modeling need to deploy Ground Control Points(GCPs),which is inefficient and costly.Control-free modeling does not require GCPs,which is efficient but not accurate.Here,we propose a 3D modeling approach for oblique photography with post-processed image control.The study was carried out in the east area of Nanjing University of Information Science&Technology.The results show that both the 3D models established by conventional modeling and post-processed image control modeling are accurate,with plane errors and elevation errors less than 0.05 m,meeting the modeling requirements of high efficiency,high precision and low cost.However,the post-processed image control modeling avoids the making and maintaining of the image control points,instead,it deploys the existing high-precision 3D model to select image control points and extract the coordinates.The proposed approach can be applied to regular updating of high-precision 3D real scene models for cities,towns,roads,etc.