Recent results have shown that iterative methods of multigrid type are very effective for regularizing purposes. In short, the reconstruction quality is of the same level or slightly better than that related to well-known regularizing procedures such as Landweber or conjugate gradient (CG) for normal equations, but the associated computational cost is highly reduced.

Here we analyze the filter features of one of these multigrid techniques in order to provide a theoretical motivation for the excellent regularizing characteristics experimentally observed in the discussed methods.