Frost Filtering Algorithm of SAR Images with Adaptive Windowing and Adaptive Tuning Factor

A Frost filtering algorithm of synthetic aperture radar (SAR) images with adaptive windowing and adaptive tuning factor is proposed to resolve the problem that the traditional Frost filtering algorithm cannot balance speckle suppression and edge preservation effectively. The tuning factor and the window influence the performance of the Frost filter significantly. When the tuning factor and the window are too big or too small, the Frost filter cannot lead to effective balance between speckle suppression and edge preservation. Through the adaptive changing of the windowing and tuning factor, the proposed algorithm can not only suppress speckle effectively, but also keep the marginal information of image better. The proposed algorithm is applied to SAR images, and it is compared with the Lee filter, the Gamma MAP filter, the traditional Frost filter, and the modified frost filter only using adaptive tuning factor. Despeckling experiments demonstrate that the proposed algorithm can suppress speckle in homogeneous regions more sufficiently, while it can preserve edge information more effectively. Therefore, the proposed algorithm achieves a better balance between speckle suppression and edge preservation.