保持弱细结构特征的SAR图象模拟退火重构方法

模拟退火 ( SA)算法最先由 White R G.用于合成孔径雷达 ( SAR)图象的降斑处理。该算法在重构均匀区域和强结构区效果有很大提高 ,但也有缺点 ,尤其是过分模糊弱细结构。本文提出了一种改进的方法 ,在 SA算法中融入了边沿检测和增强步骤 ,使弱细结构得以增强并在退火过程中保持。为配合此方法 ,采用平稳下降的指数温度规划取代对数形式。通过仔细调整算法过程 ,可使新方法保留 SAR图象中的很多细小结构 ,而不使其他均匀的和强结构场景性能恶化 ,同时也没有引入其他缺陷。改进的算法更加适于中、低分辨率的 SAR图象降斑处理

SAR Image Reconstruction by a Thin and Weak Feature Preserving Simulated Annealing Approach

The simulated annealing (SA) algorithm , originally developed by White R G for speckle reduction of synthetic aperture radar (SAR) images, shows significant improvement on the reconstruction of both homogeneous and strong structured areas. But his algorithm also has drawbacks itself, especially over smooth thin and weak textures and structures. In this study, a modified version of the algorithm is presented. The SA approach is extended to incorporate an edge detection and enhancement step that makes thin and weak structures strong enough to be preserved during annealing. To cooperate with this method, a temperature steadily decreased exponential schedule is adopted instead of the logarithm plan. By delicately adjusting the SA process, the proposed approach can well preserve many fine features in an SAR image while not degrading performance of other scenes such as homogeneous and strong structured areas and without other additional image defects. This feature makes the algorithm more suitable for filtering low and medium resolution SAR images.