After reading the authors' rebuttal, the reviewers discussed their concerns about this paper. Ultimately, a consensus was not reached as reviewer #3 feels that some of her/his concerns were not properly addressed in the authors' feedback. The other reviewers are positive with respect to the paper (especially thanks to the promising experimental results), but they share one of the concerns of reviewer #3, i.e., the definition of ``optimal f-divergence'' and the convergence properties of the proposed approach. I agree with them that the paper has merits and the ideas contained in the paper are interesting, so I propose to accept it, but I recommend that the authors take the issues raised in the reviews seriously and address them carefully in the final version of the paper.