Object-Based Image Retrieval Using Semi-Supervised Multi-Instance Learning

Aiming at the problem of object-based image retrieval, a novel semi-supervised multi-instance learning (MIL) algorithm based on RS (rough set) attribute reduction and transductive support vector machine (TSVM) has been presented-RSTSVM-MIL algorithm. This algorithm regards the whole image as a bag, and the low-level visual feature of the segmented regions as instances, in order to transform every bag to a single sample, RSTSVM-MIL first generates a collection of "visual-word" to construct projection space by K-means clustering method in the instance feature space, then a nonlinear mapping is defined using these "visual-word" and maps every bag to a point in the projection space, extracting all bags' projection feature, which converts MIL problem to a standard supervised learning problem. Finally, in order to improve the efficiency of classifier training and to use a large amount of unlabeled image together with the labeled image to build better classifiers, we use RS (rough set) method to reduce the redundant information in projection feature firstly, then semi-supervised learning algorithm TSVM be used to train classifier. Experimental results on the SIVAL image set show that solving MIL problems using semi-supervised learning is feasible, and the RSTSVM-MIL is competitive with other state-of-the-art MIL algorithms in object-based image retrieval problem.