摘要
由于SAR工作原理跟光学遥感成像技术截然不同,而经典同名点匹配方法已不能完全满足SAR自动配准需要。为了快速有效地进行SAR影像配准,基于SAR影像自动配准技术的发展,提出了一种新颖的高分辨率SAR影像同名点自动匹配算法,该算法首先创建金字塔影像,同时在金字塔影像上回溯搜索,以确定初始变换函数类型及相应的变换参数;然后通过分层回溯逐层加密控制点来解求最佳变换函数类型及相应变换参数;最后在原始影像分辨率下修正同名点坐标,以获取最终匹配同名点对。这种分层回溯策略不仅很好地解决了同名点搜索计算复杂度问题,使获取的同名点对分布更趋均匀、精度更高,而且能确保每层变换函数达到全局最小二乘最优。另外,以高分辨率SAR影像为实验数据进行的实验结果表明,该同名点搜索算法不仅计算时间可由221 s缩短至34 s,而且可达到0.284 636 p ixels的配准精度。
The imaging system of SAR is totally different from optic＇ s, thereby, the traditional matching method can not be fully suitable in the case of SAR image process. Based on the development of automatic registration of SAR images, in this paper, a novel method of automatic matching of tie-points with high-resolution SAR is proposed. The method consists of three steps： In the first step, back-trace is employed to determine the type and parameters of the initial mapping function after pyramid images are created; secondly, layered back-trace is used to increase control points, the type and parameters of the optimal mapping function are resolved afterwards; finally, the coordinates of control points are revised on original image resolution in order to acquire the final matched tie-points. The strategy of layered back-trace is employed in this algorithm, which not only resolves the problem of compute efficiency, achieves a higher matching accuracy with more evenly distributed tie-points, but also insures the mapping function to be optimal in MMSE（ mean minimum square error） sense. High-resolution airborne SAR images are used in our experiments, and the result shows the proposed algorithm is efficient and effective, where comparing with a traditional method which costs 221s computer time, our method only costs 34s; what is more, it can achieve a sub-pixel matching precision, equaling to 0. 284 636 pixels.
出处
《中国图象图形学报》
CSCD
北大核心
2006年第9期1276-1281,共6页
Journal of Image and Graphics
基金
国家重点基础研究发展规划"973"计划项目(2001CB309406)
关键词
分层回溯
同名点匹配
高分辨率SAR
layered back-trace, matching of tie-points, high-resolution SAR
