Spectral pre-adaptation for two-step arbitrary-shape-support image restoration

In recent years, boundary problems associated to image restoration have attracted the attention of imaging scientists. We explore here the case of arbitrary boundary shapes (like blurred-background images), starting from a general discussion and advancing towards realist conditions, with simulations and real photographic images. We describe our Spectral-Pre-Adaptation (SPA) method, and compare it to the successful unconstrained boundary conditions Alternating Direction Method of Multipliers (UBC ADMM) method. Preliminary results indicate that SPA, combined with efficient restoration algorithms, such as Constrained Dynamic L2-relaxed L0, may set the new state-of-the-art, in performance and computational terms, for this kind of problems.