In the framework of the interactive search in image databases, we are interested in similarity measures able to learn during the search and usable in real-time. Images are represented by adjacency graphs of fuzzy regions. In order to compare attributed graphs, we employ kernels on graphs built on sets of paths. In this paper, we introduce a fast kernel function whose similarity is based on several matches. We also introduce new features for edges in the graph. Experiments on a specific database having objects with heterogeneous backgrounds show the performance of our object retrieval technique.