Improved bilateral filtering for SAR image despeckling

To effectively preserve edges of synthetic aperture radar (SAR) images while cleanly despeckling, an improved bilateral filtering algorithm (IBF) is proposed. A threshold value is first calculated, which is used to distinguish whether the current pixel and its neighbouring pixels are homogeneous or not. Then, bilateral filtering (BF) is improved by reducing its two parameters to one, which emphasises the contribution of adjacent homogeneous pixels to the approximation of the current pixel. Finally, IBF is applied to remove speckles. The despeckling results for SAR images show that the visual quality and evaluation indexes of IBF outperform those of enhanced Lee filtering (ELF) and BF.