The evaluation method proposed here follows the idea presented in [Riot et al., 2017] which examines the residual image and looks for possible remaining structural elements in this residual image. Unlike maximum ENL estimation or αβ estimation [Gomez et al., 2016] method, this method is automatic and does not rely on a supervised selection of homogeneous regions. It also provides a global score for the whole image.
Figure 1. Denoising real Sentinel-1 images over the region of Saclay (the original noisy image is available in figure 6.2(a)). Left column : denoised results ; middle column : residual ratio images ; right column : residuals evaluation results with displaying value range [0, 4]. 64 Sentinel-1 images are used.