Visual Affinity Propagation Improves Sub-topics Diversity without Loss of Precision in Web Photo Retrieval

Abstract

This paper demonstrates that Affinity Propagation (AP) outperforms Kmeans for sub-topic clustering of web image retrieval. A SVM visual images retrieval system is built, and then clustering is performed on the results of each topic. Then we heighten the diversity of the 20 top results, by moving into the top the image with the lowest rank in each cluster. Using 45 dimensions Profile Entropy visual Features, we show for the 39 topics of the imageCLEF08 web image retrieval clustering campaign on 20K IAPR images, that the Cluster-Recall (CR) after AP is 13% better than the baseline without clustering, while the Precision stays almost the same. Moreover, CR and Precision without clustering are altered by Kmeans. We finally discuss that some high-level topics require text information for good CR, and that more discriminant visual features would also allow Precision enhancement after AP.

Work supported by the French National Agency of Research (ANR-06-MDCA-002) & Research Fund for the Dr. Program of Higher Education of China (200803591024). We thank P. Mulhem (LIG) for providing the training labels and Kmeans results.