真正射影像制作的遮挡区检测方法研究

Detecting method of occluded area in true orthophoto generation

遮挡区检测是真正射影像制作的必要环节之一。本文首先对现有方法进行总结、分析;然后提出一种基于阴影测试技术的快速检测方法,通过成像过程的模拟,将遮挡区检测问题转化为一个阴影测试问题,基于Z-Pass算法,利用三维图形绘制流水线的模板缓存和深度缓存,能够快速确定遮挡区域;最后,进行试验验证,结果表明:利用本文提出的方法仅需一次三维图形绘制操作,即可在很短的时间内完成大区域的建筑物遮挡检测。

Oech.led area detecting is an indispensable step of True Orthophoto generation. This paper first summarized and analyzed existing methods; then proposed a new quickly detecting method based on shadow-testing technology, which translated occluded areas detecting problem into a shadow-testing problem by simulating shoot processing, and using stencil buffer and depth buffer of 3D pipe line based on Z-pass algorithm quickly drew the occluded areas; at last, an experiment indicated that this method could accomplish occluded detecting of a large zone in very short time by 3D drawing only once.