基于图的航空图像与GIS模型匹配算法

Matching Algorithm of Aerial Image and GIS Model Based on Graph

地理信息系统(GIS)采用语义描述,图像中缺少颜色及灰度信息,只能基于其结构特征进行匹配。受目前图像处理技术限制,从图像中提取的特征信息量少、精度受限、且往往含有噪声。针对上述问题,提出一种基于图的航空图像与GIS模型匹配算法。基于UWG-SA方法分别对GIS与实时图像特征自动构建图,根据设定的相容函数,采用分级指派方法计算图的全局相容度,并给出主方向方法去除误匹配,求解变换参数。实验结果表明,该算法匹配概率为98.5%,平均匹配误差为8.54 m,平均耗时为0.075 s,可满足飞行器导航需求。

Geographic Information System（GIS） is described by semantics. There is no color or gray information in GIS. The matching between aerial images and GIS has to rely on structural features. Restricted by current image processing techniques, the features extracted from images are low informative, have low precision, and usually contain noises. Aiming at these problems, a graph-based matching framework is proposed to align the GIS model and the aerial image. The Undirected Weighted Graphs（UWG） are constructed automatically using the angle between segment lines called UWG-SA for GIS and the extracted image features, respectively. A Graduated Assignment（GA） method is performed to find the global correspondences. It uses the main-direction method to eliminate the incorrect match sets and get the transformation parameters. Experimental results show that the matching probability is about 98.5%, the average matching error is about 8.54 m, and the average cost time is 0.075 s. The algorithm can basically meet the demand for aircraft navigation.