Dual-perspective multi-instance embedding learning with adaptive density distribution mining

Multi-instance learning (MIL) is a potent framework for solving weakly supervised problems, with bags containing multiple instances. Various embedding methods convert each bag into a vector in the new feature space based on a representative bag or instance, aiming to extract useful information from the bag. However, since the distribution of instances is related to labels, these methods rely solely on the overall perspective embedding without considering the different distribution characteristics, which will conflate the varied distributions of instances and thus lead to poor classification performance. In this paper, we propose the dual-perspective multi-instance embedding learning with adaptive density distribution mining (DPMIL) algorithm with three new techniques. First, the mutual instance selection technique consists of adaptive density distribution mining and discriminative evaluation. The distribution characteristics of negative instances and heterogeneous instance dissimilarity are effectively exploited to obtain instances with strong representativeness. Second, the embedding technique mines two crucial information of the bag simultaneously. Bags are converted into sequence invariant vectors according to the dual-perspective such that the distinguishability is maintained. Finally, the ensemble technique trains a batch of classifiers. The final model is obtained by weighted voting with the contribution of the dual-perspective embedding information. The experimental results demonstrate that the DPMIL algorithm has higher average accuracy than other compared algorithms, especially on web datasets.