数字正射影像镶嵌的质量评价方法

Quality Evaluation Method for the Results of Digital Orthophoto Mosaic

针对数字正射影像镶嵌结果的质量评价,提出了一种基于缓冲区影像的、兼顾辐射一致性和几何一致性指标的定量评价方法.首先以镶嵌线为中心建立缓冲区,分别从镶嵌线对应的左右影像中提取缓冲区影像,然后以此为基础进行质量评价指标的计算,其中辐射一致性评价采用灰度反差系数及统一亮度分布等指标,几何一致性评价采用加速鲁棒特征(speeded-up robust features,SURF)匹配点的偏移距离等指标,从而得到镶嵌质量的评价结果.分别采用德国Vaihingen地区的36幅城区正射影像和中国湖北省恩施地区的36幅山区正射影像为实验数据集,对由Arc GIS、Ortho Vista和DPGrid 3种商业软件得到的影像镶嵌结果进行了质量评价,验证了该方法的有效性.

For the quality evaluation of the Digital Orthophoto mosaic, a quantitative evaluation method, which is based on the buffer images and includes both the radiometric consistency and geometric consistency indexes, is presented in this paper. Firstly, the buffer zones are built around the seamline, and the buffer images are obtained from the left and right images corresponding to the seamline. Then based on this, the quality evaluation indexes can be calculated, among them, the radiometric consistency is mainly evaluated by the indexes of the gray contrast coefficient and the Uniform Intensity-Distribution, the geometric consistency is mainly evaluated by using the offset distance of the SURF （speeded-up robust features） feature matching points. Finally, the evaluation results of mosaic quality are obtained. Using 36 urban orthophotos of the Vaihingen area of Germany and 36 mountain orthophotos of the Enshi area of China as an experiment data set, the quality evaluation was carried out for the mosaic results respectively obtained by three business softwares of ArcGIS, OrthoVista and DPGrid, which verifies the effectiveness of the proposed method.