面向大规模真正射影像生产的快速遮蔽检测方法

A Fast Approach to Detect Occlusions for Large-scale True Orthophoto Generation

根据径向投影高度角的变化进行遮蔽区域分析,利用计算数学理论推导各个步骤的计算复杂度,并利用极值理论确定具有最小复杂度的方法.实验表明,基于径向投影高度角变化的方法可以有效解决因地形起伏、分辨率差异和高窄墙体引起的各类伪可见和伪遮挡问题.最优分割的径向扫描方法具有最高的计算效率和最平缓的效率曲线,有利于大规模高质量真正射影像的生产.

The proposed method detects the occlusions by checking the off-nadir angle of the line of sight connecting the perspective centre with the object point of interest. Then, the algorithm complexity of all the steps is estimated according to the mathematical computation theory. Finally, a method of the least complexity is obtained on the basis of the extreme point theory of differential calculus. Experiments show that the proposed method is efficient to avoid ＂M- portion＂, false occlusions and false visibilities caused by the rolling area, the incompatibility between the DSM and ground image resolution. It is a robust, accurate, fast and effective approach to generate high quality true orthophoto on a large scale.