@inproceedings{2008-C-BregmanCentroids-ICPR , author={Frank Nielsen and Richard Nock} , title={Bregman sided and symmetrized centroids} , booktitle={International Conference on Pattern Recognition (ICPR)} , month={December} , year={2008} , pages={1-4} , address={Tampa, Florida, USA} , doi={10.1109/ICPR.2008.4761794} , abstract={We generalize the notions of centroids and barycenters to the broad class of information-theoretic distortion measures called Bregman divergences. Because Bregman divergences are typically asymmetric, we consider both the left-sided and right-sided centroids and the symmetrized centroids, and prove that all three are unique. We give closed-form solutions for the sided centroids that are generalized means, and design a provably fast and efficient approximation algorithm for the symmetrized centroid based on its exact geometric characterization that requires solely to walk on the geodesic linking the two sided centroids. } }