Conversational Composed Retrieval with Iterative Sequence Refinement

摘要

Due to the progress of large-scale multimodal model pretraining, existing cross-modal retrieval techniques is accurate to align text description to the target image when they show close and clear semantic correspondence. However, in real situations, users only provide ambiguous text queries, making it difficult to retrieve the desired images. To address this issue, we introduce the conversational composed retrieval paradigm, inspired by conversational search which models complex user intent through iterative interaction. This paradigm enhances the model capacity in learning fine-grained correspondences. To train the cross-modal conversational retrieval, we propose the Iterative Refining Retrieval (IRR) framework. It formalizes the reference images and modification texts in each session as a multimodal sequence, which is fed into the generative model to predict the information in the sequence autoregressively, and ultimately predicting the target image feature. In the conversational retrieval paradigm, the model refines the learned correspondences based on the interaction in the later stage of the retrieval session, thus captures fine-grained semantic correspondence to enforce the cross-modal representation. We propose a domain-specific multimodal pretraining method and the full sequence sampling augmentation method to fully utilize the session information. Extensive experiments demonstrate that the iterative refining retrieval method achieves state-of-the-art performance on sessions of varying lengths.