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

The traditional Frost filter is improved by the adaptive windowing and adaptive tuning factor for the synthetic aperture radar (SAR) images in this letter. The proposed double-adaptive Frost filter simultaneously makes the window size and the tuning factor adaptively adjusted in terms of the regional characteristics, leading to an effective balance between speckle suppression and edge preservation. The despeckling experiments on the simulated and real SAR images demonstrate that in comparison to the Lee filter, the Gamma maximum a posteriori (MAP) filter, the traditional Frost filter, and the Frost filter only with the adaptive tuning factor, the double-adaptive Frost filter sufficiently suppresses the speckle in homogeneous regions and in edge regions and effectively preserves the edges and fine details.