SAR image despeckling combining target detection with improved nonlocal means

To effectively preserve targets such as edges and dots of synthetic aperture radar (SAR) images while cleanly removing noise, a despeckling strategy is proposed. Both despeckling results of bilateral filtering and an improved nonlocal means algorithm (INLMeans) are first utilised to detect targets. Then, the detected targets are removed from the SAR image and INLMeans is employed to denoise the targets-removed image. Finally, the removed targets are added to the despeckled targets-removed image. Experimental results show that the visual quality and evaluation indexes of the proposed algorithm outperform those of the anisotropic diffusion and INLMeans.