Speckle Noise Removal Technique in SAR Images using SRAD and Weighted Least Squares Filter

Abstract

In the process of obtaining synthetic aperture radar (SAR) images, speckle noise exhibited in the SAR images. Speckle noise in the SAR images degrades an image quality and become difficult to interpret the image. Speckle noise reduction technique is a crucial step for using various application of SAR images. In this paper, we proposed a novel algorithm based on speckle reducing anisotropic diffusion (SRAD) and weighted least squares (WLS) filter for removing speckle noise and preserving edge information. The SRAD filter is applied as a preprocessing filter. A logarithmic transformation employed to convert a multiplicative noise remaining in the SRAD filter result image. The multiplicative noise changed as an additive noise. The additive noise in the SRAD filtering result image removed by the WLS filter. We can obtain a despeckled image employing an exponential transform. Experimental results demonstrate that the proposed method exhibits the best speckle noise reduction and edge preservation performance than the conventional filtering techniques.