Speckle noise reduction in SAR imaging using lattice filters based subband decomposition

Abstract

A new speckle reduction algorithm based on lattice filters for SAR imaging is presented. In the new method, the subband decomposition of the speckled image is performed using lattice filters. The noisy image is decomposed into subband images using high-pass and low-pass filters having lattice structure, then a threshold value is estimated according to noise variance in each subband and soft-thresholding is applied on the subband images. The despeckled image is obtained from the thresholded subband images using the inverse lattice filter. The proposed speckle reduction method is applied to RADARSAT/SAR images. The performance of the proposed method has also been compared with median filtering, and discrete and stationary wavelet transform based speckle reduction methods. Results show that the proposed method may be used efficiently for speckle noise reduction in SAR images.