Query-dependent visual dictionary adaptation for image reranking.

Although text-based image search engines are popular for ranking images of user's interest, the state-of-the-art ranking performance is still far from satisfactory. One major issue comes from the visual similarity metric used in the ranking operation, which depends solely on visual features. To tackle this issue, one feasible method is to incorporate semantic concepts, also known as image attributes, into image ranking. However, the optimal combination of visual features and image attributes remains unknown. In this paper, we propose a query-dependent image reranking approach by leveraging the higher level attribute detection among the top returned images to adapt the dictionary built over the visual features to a query-specific fashion. We start from offline learning transposition probabilities between visual codewords and attributes, then utilize the probabilities to online adapt the dictionary, and finally produce a query-dependent and semantics-induced metric for image ranking. Extensive evaluations on several benchmark image datasets demonstrate the effectiveness and efficiency of the proposed approach in comparison with state-of-the-arts.