An Algorithmic Framework to the Optimal Mapping Function by a Radial Basis Function Neural Network

To solve the problem of learning a mapping function from low-level feature space to high-level semantic space, we propose a relevance feedback scheme which is naturally conducted only on the image manifold in question rather than the total ambient space. While images are typically represented by feature vectors, the natural distance is often different from the distance induced by the ambient space. The geodesic distances on manifold are used to measure the similarities between images.Based on user interactions in a relevance feedback driven query-by-example system, the intrinsic similarities between images can be accurately estimated. We then develop an algorithmic framework to approximate the optimal mapping function by a radial basis function (RBF) neural network. The semantics of a new image can be inferred by the RBF neural network. Experimental results show that our approach is effective in improving the performance of content-based image retrieval systems.