Synthetic Aperture SONAR image despeckling methods assessment

SAS (synthetic aperture sonar) has been used in sea bed imagery. Indeed high resolution images provided by SAS are of great interest, especially for the detection, localization and eventually classification of objects lying on sea bed. But as any image obtained with a coherent system, SAS images are highly corrupted by a granular multiplicative noise, called speckle noise which reduces spatial and radiometric resolutions. The appraisal of despeckling methods or in more general denoising methods is a never ending discussion. Since, these techniques are applied on images, one can somewhat merely look at the image and have a good idea of the general outcomes. Yet, in practice this would take too much time and overall would not be objective at all. Thus, people doing research work on filter wanted to assess their developed methods and tried to find out objective assessing processes. In this paper, we present some of the scientific literature proposals and, by the way of experiments on real data, discuss about them.