Federated learning for supervised cross-modal retrieval

In the last decade, the explosive surge in multi-modal data has propelled cross-modal retrieval into the forefront of information retrieval research. Exceptional cross-modal retrieval algorithms are crucial for meeting user requirements effectively and offering invaluable support for subsequent tasks, including cross-modal recommendations, multi-modal content generation, and so forth. Previous methods for cross-modal retrieval typically search for a single common subspace, neglecting the possibility of multiple common subspaces that may mutually reinforce each other in reality, thereby resulting in the poor performance of cross-modal retrieval. To address this issue, we propose a Federated Supervised Cross-Modal Retrieval approach (FedSCMR), which leverages competition to learn the optimal common subspace, and adaptively aggregates the common subspaces of multiple clients for dynamic global aggregation. To reduce the differences between modalities, FedSCMR minimizes the semantic discrimination and consistency in the common subspace, in addition to modeling semantic discrimination in the label space. Additionally, it minimizes modal discrimination and semantic invariance across common subspaces to strengthen cross-subspace constraints and promote learning of the optimal common subspace. In the aggregation stage for federated learning, we design an adaptive model aggregation scheme that can dynamically and collaboratively evaluate the model contribution based on data volume, data category, model loss, and mean average precision, to adaptively aggregate multi-party common subspaces. Experimental results on two publicly available datasets demonstrate that our proposed FedSCMR surpasses state-of-the-art cross-modal retrieval methods.