Despeckling algorithm for reducing speckle noise in images generated from active sensors

Abstract

Synthetic aperture radar (SAR) images can be utilised in various fields because they are not affected by the time of day or weather conditions. However, in the process of employing active sensors to obtain a SAR image, speckle noise is generated in the image. Speckle noise degrades the ability of computer vision to observe the Earth. To improve imaging performance, an algorithm for removing speckle noise is necessary. For this purpose, the authors propose a speckle-noise removal algorithm. A speckle reducing anisotropic diffusion filter is employed as a pre-processing filter, in which multiplicative speckle noise can be converted into additive noise using a logarithmic transformation. To remove the additive noise, they use a weighted guided image filter. Experimental results indicate that the proposed method exhibits improved speckle noise suppression and edge preservation results compared with those of existing methods.