Merging results of distributed image libraries

Exploitation of information repositories available on the Internet requires users to separately query each repository and manually gather retrieved results. Such a solution could be simplified by using a centralized server that acts as a gateway between the user and repositories: the centralized server forwards the user query to federated repositories and fuses retrieved documents for presentation to the user. To perform these tasks efficiently, the centralized server should perform two main functions: resource selection and data fusion. The former is required to forward the user query only to the repositories that are candidate to contain relevant documents. The latter is used to gather all retrieved documents and conveniently arrange them for presentation to the user. In the case of image repositories, data fusion is particularly challenging owing to the difficulty to normalize document scores returned by different repositories. In this paper a novel solution is presented for fusion of results returned by different image repositories. Experimental results are presented that show the potential of the proposed approach.