DEM迭代法制作山区辅助立体影像中循环矩形的处理

Solution for Circular Rectangle in Generating Stereo Aided Image in Mountains by DEM Iteration Method

以数字正射影像为基础，在DEM支持下，通过人工引入投影光线，制作立体辅助影像。辅助影像与原正射影像共同构建立体正射影像对，产生与实地相似的几何模型，进行立体观察与量测，可解决三维量测问题。在山区，DEM迭代生成立体辅助影像时会出现不收敛情况，会产生循环矩形问题。对角线迭代法是DEM迭代法的一种改进，是逐步逼迫最终影像点位的算法。本文以固定角度法为例引入人工投影光线，探讨采用对角线DEM迭代法来解决循环矩形问题，并给出实验成果及高程精度检测。

Based on digital ortho - image, the projection light is introduced artificially to generate stereo auxiliary images under the support of DEM. The auxiliary image and the original orthoimage are used to construct the stereo orthoimage pair together, and generate the geometric model similar to the field and conduct the three - dimensional observation and measurement, which can solve the problem of three - dimensional measurement. In mountainous area, the DEM iteration could cause misconvergenee in the process of generating auxiliary stereo image and produce circular rectangle. Diagonal iteration is an improvement on the DEM iteration, which is a kind of algorithm that gradually get close to the final image point. In this paper, the fixed angle method is used as an example to introduce artificial projection light and the diagonal DEM iteration is used to solve the circular rectangle problem. Besides, the experimental achievements and height accuracy are given.