The paper has initially received mixed reviews, but post-rebuttal the expert reviewers have converged to the decision that the paper is above the acceptance threshold and that the proposed regularization is of wide interest to the community. Accept. The authors are encouraged to incorporate the extra experimental results from the rebuttal into the final version of the paper. Also, the related work section should be revised by incorporating relevant works pointed by the reviewers (and as promised in the rebuttal).