An Explicit Solution for Image Restoration using Markov Random Fields

Image restoration and denoising is an essential preprocessing step for almost every subsequent task in computer vision. Markov Random Fields offer a well-founded, sophisticated approach for this purpose, but unfortunately the associated computation procedures are not sufficiently fast, due to a high-dimensional optimization problem. While the increase of computing power could not solve this runtime issue appropriately, we address it in a mathematical way: we suggest an analytical solution for the optimum of the inference problem, which provides desirable mathematical properties. In practice, our new method accelerates the runtime via reducing the computational complexity of the image restoration task by orders of magnitude, independent from the smoothing intensity. As a result, Markov Random Fields can be considered for modern big data problems in computer vision, especially if numerous images with equal sizes are processed.This is a post-peer-review, pre-copyedit version of an article published in Journal of Signal Processing Systems. The final authenticated version is available online at: http://dx.doi.org/10.1007/s11265-019-01470-