一种非下采样轮廓波变换的机载SAR图像增强

An nonsubsampled contourlet transform for airborne SAR image enhancement

针对机载合成孔径雷达(SAR)影像因入射角、侧视距离和后向散射系数差异导致的内部亮度不均衡、边缘细节特征模糊等图像质量问题,采用一种基于非下采样轮廓波变换(NSCT)的图像增强处理方法来提升视觉效果,增强图像质量。相对于传统图像增强算法,该方法能够更好地解决SAR影像的辐射差异:结构相似度与平均梯度表现最优,在较好保持原始影像信息的基础上,亮度不均匀现象得到有效改善,对机载SAR影像的视觉效果有很大的提高。

A nonsubsampled contourlet transform(NSCT)was applied to enhance the image quality of airborne synthetic aperture radar(SAR)images due to differences in incidence angle,side viewing distance and backscatter coefficients,resulting in internal brightness imbalance and blurred edge detail features.Compared with traditional image enhancement algorithms,NSCT method could better resolve the radiometric differences of SAR images:the structural similarity and the average gradient performed optimally,and the brightness non-uniformity was effectively improved on the basis of better maintaining the original image information,which had greatly improved the visual effect of airborne SAR images.