Efficient marginal likelihood optimization in blind deconvolution
Anat Levin, Yair Weiss, Frédo Durand, William T. Freeman · 2011
In blind deconvolution one aims to estimate from an input blurred image y a sharp image x and an unknown blur kernel k. Recent research shows that a key to success is to consider the overall shape of the posterior distribution p(x, k\y) and not only its mode. This leads to a distinction between MAPx, kstrategies which estimate the mode pair x, k and often lead to undesired results, and MAPkstrategies which select the best k while marginalizing over all possible x images. The MAPkprinciple is significantly more robust than the MAPx, kone, yet, it involves a challenging marginalization over latent images. As a result, MAPktechniques are considered complicated, and have not been widely exploited. This paper derives a simple approximated MAPkalgorithm which involves only a modest modification of common MAPx, kalgorithms. We show that MAPkcan, in fact, be optimized easily, with no additional computational complexity.