一种改进的基于上下文信息的多源数据融合目标提取方法

An Improved Method for Object Extracting based on Context Information Using Multisouce Data

拟提出一种综合利用航空影像与LiDAR数据提取山地滚石信息新方法:首先对影像进行多尺度分割得到分割对象,同时对LiDAR数据进行分类、插值和差分等处理获取高程信息。然后依据影像分割对象计算基于可见光波段的差异植被指数并用于去除植被信息的干扰,得到非植被影像分割对象。为了有效利用阴影,针对航空影像提出归一化差异阴影指数并根据阈值分割得到阴影对象。然后利用提出的基于阴影和高程的滚石信息自动提取算法对获取的非植被影像分割对象进行滚石初步提取,再根据实际需求设定高程阈值过滤得到最终的滚石信息。最后,以香港某地区的航空影像和LiDAR数据为基础,对提出的方法进行实例验证,结果表明该方法能够较好地提取滚石并有效地区分裸露基岩、道路等与滚石光谱信息相近的地物,滚石提取精度达到88%以上,基本能满足地政部门滚石防护的需求。

This paper proposed a new method which combines the airborne LiDAR data with aerial image to extract Rolling Stones on mountainous.Firstly,the aerial image is processed with multi-scale segmentation to get segmentation objects, and the LiDAR data are processed by classification,interpolation, difference for elevation information.Then compute the segmentation object based on visible-band difference vegetation index to remove the interference of vegetation information, and the nonvegetated segmentation objects are obtained.In order to effectively use the shadow, this paper put forward the normalized difference shadow index and use threshold segmentation to get shadow object. And then the automatic extraction algorithm based on the shadow and elevation information is used to preliminary obtain the rolling stones information. Finally, The height threshold filtering is set according to the actual demand to get the final rolling information.This paper took a certain area of Hong Kong aviation image and LiDAR data as experimental data to validate the proposed method.The results show that the method can well extract the Rolling Stones and effectivly distinguish the exposed bedrock, roads and similar spectral information of ground objects as Rolling Stones.The extraction accuracy of Rolling Stones is above 88% which basically satisfies the needs of rockfall in lands department.