Analysis of Synthetic Aperture Radar Images Using Brute Force Thresholding and Gradient Guide Filters

Nowadays Imaging Radars (IR) finds many applications, in both civilian and defense fields to observe various scenarios over the horizon. Due to the rapid development of space borne and air borne platforms Synthetic Aperture Radars (SAR) becomes as an electronic eye to monitor different terrain features, various activities on the globe. As a result, analysis of SAR images is desirable to obtain high resolution electromagnetic (EM) images. In order to fulfill these requirements we propose a novel enhancement technique to de-speckle SAR images and to provide high resolution SAR images for the specific terrain monitoring. The proposed technique is a hybrid version of an improved brute force thresholding (BFT) based undecimated wavelet transform. The improved BFT combined with total variance process removes the speckle noise by preserving texture and edges. After this de-speckling process the image undergoes an enhancement process by gradient domain guided image filter (GDGIF). This GDGIF makes sharp enhancement and facilitates good quality SAR image for terrain analysis. GDGIF performs better than conventional guided image filter (GIF) and weighted guided filter (WGF). Simulation results confirm that the proposed realizations are well suited for real time applications. By comparing performance measures shown in Table II, the proposed method achieves better results in terms of minimum MD of 0.210, minimum MSE of 2.72E-04 and maximum PSNR of 35.658.