Speckle filtering in synthetic aperture radar (SAR) and polarimetric SAR (PolSAR) images is indispensable before the extraction of the useful information. The minimum mean square error estimate of the filtered pixels conducted to the definition of a linear rule between the values of the filtered pixels and their variances. Hence, the filtered pixel for infinite number of looks (INL) is predicted by a linear regression of means and variances for various window sizes. In this article, the infinite number of looks prediction (INLP) filter is explored in details to emphasize its ability to reduce speckle and preserve the spatial details. Then, the linear regression rule has been adapted to PolSAR context in order to preserve the polarimetric information. The number of the processed pixels used in the linear regression is adjusted to the variability of the scene. This effort increased the filtering performances. The reduction of the correlation between the pixels which constitutes an additional filtering criterion is discussed. Compared to the initially applied filter, the results showed that the improved INLP filter increased in speckle reduction level, augmented the preservation of the spatial details, increased the spatial resolution, reduced the correlation between the pixels and better preserved the polarimetric information. Simulated, one-look and multilook real PolSAR data were used for validation.

中文翻译：

---

无限次数预测技术的极化SAR图像滤波

在提取有用信息之前，合成孔径雷达（SAR）和极化SAR（PolSAR）图像中的斑点滤波是必不可少的。滤波像素的最小均方误差估计用于在滤波像素的值及其方差之间定义线性规则。因此，通过对各种窗口大小的均值和方差的线性回归，可以预测出无数个外观（INL）的滤波后像素。在本文中，将详细探讨无限数量的外观预测（INLP）过滤器，以强调其减少斑点和保留空间细节的能力。然后，线性回归规则已适应PolSAR上下文，以保留极化信息。线性回归中使用的已处理像素数将根据场景的可变性进行调整。这种努力提高了过滤性能。讨论了构成附加滤波标准的像素之间的相关性的降低。与最初使用的滤波器相比，结果表明改进的INLP滤波器提高了斑点减少水平，增强了对空间细节的保留，提高了空间分辨率，减少了像素之间的相关性，并更好地保留了偏振信息。模拟的，单视和多视的真实PolSAR数据用于验证。与最初使用的滤波器相比，结果表明改进的INLP滤波器提高了斑点减少水平，增强了对空间细节的保留，提高了空间分辨率，减少了像素之间的相关性，并更好地保留了偏振信息。模拟的，单视和多视的真实PolSAR数据用于验证。与最初使用的滤波器相比，结果表明改进的INLP滤波器提高了斑点减少水平，增强了对空间细节的保留，提高了空间分辨率，减少了像素之间的相关性，并更好地保留了偏振信息。模拟的，单视和多视的真实PolSAR数据用于验证。