13. In a computing environment, a system comprising: one or more processors; a mechanism implemented on the one or more processors and configured to identify one or more word exemplars and one or more image exemplars for a tagged image collection, each image of the tagged image collection having one or more associated text labels, the mechanism including a heterogeneous affinity propagation component configured to propagate homogeneous messages within images based upon one or more similarities between the images, homogeneous messages within words of the one or more associated text labels based upon similarities between the words, and heterogeneous messages between the images and the words based upon the relationships between one or more of the images and the words, wherein the one or more word exemplars comprise a set of one or more words that represent at least a subset of the tagged image collection based on the homogeneous messages within the words propagated by the heterogeneous affinity propagation component, and wherein the one or more image exemplars comprise a set of one or more images that represent at least the subset of the tagged image collection or another subset of the tagged image collection based on the homogeneous messages within the images propagated by the heterogeneous affinity propagation component.
13. In a computing environment, a system comprising: one or more processors; a mechanism implemented on the one or more processors and configured to identify one or more word exemplars and one or more image exemplars for a tagged image collection, each image of the tagged image collection having one or more associated text labels, the mechanism including a heterogeneous affinity propagation component configured to propagate homogeneous messages within images based upon one or more similarities between the images, homogeneous messages within words of the one or more associated text labels based upon similarities between the words, and heterogeneous messages between the images and the words based upon the relationships between one or more of the images and the words, wherein the one or more word exemplars comprise a set of one or more words that represent at least a subset of the tagged image collection based on the homogeneous messages within the words propagated by the heterogeneous affinity propagation component, and wherein the one or more image exemplars comprise a set of one or more images that represent at least the subset of the tagged image collection or another subset of the tagged image collection based on the homogeneous messages within the images propagated by the heterogeneous affinity propagation component. 14. The system of claim 13 wherein the heterogeneous message propagation component further determines a relative measure of how well each image serves as an exemplar based on whether a paired word is an exemplar.