AMC: Adaptive Multi-expert Collaborative Network for Text-guided Image Retrieval

Text-guided image retrieval integrates reference image and text feedback as a multimodal query to search the image corresponding to user intention. Recent approaches employ multi-level matching, multiple accesses, or multiple subnetworks for better performance regardless of the heavy burden of storage and computation in the deployment. Additionally, these models not only rely on expert knowledge to handcraft image-text composing modules but also do inference by the static computational graph. It limits the representation capability and generalization ability of networks in the face of challenges from complex and varied combinations of reference image and text feedback. To break the shackles of the static network concept, we introduce the dynamic router mechanism to achieve data-dependent expert activation and flexible collaboration of multiple experts to explore more implicit multimodal fusion patterns. Specifically, we construct AMC, our Adaptive Multi-expert Collaborative network, by using the proposed router to activate the different experts with different levels of image-text interaction. Since routers can dynamically adjust the activation of experts for the current samples, AMC can achieve the adaptive fusion mode for the different reference image and text combinations and generate dynamic computational graphs according to varied multimodal queries. Extensive experiments on two benchmark datasets demonstrate that due to benefits from the image-text composing representation produced by an adaptive multi-expert collaboration mechanism, AMC has better retrieval performance and zero-shot generalization ability than the state-of-the-art method while keeping the lightweight model and fast retrieval speed. Moreover, we analyze the visualization of path activation, attention map, and retrieval results to further understand the routing decisions and semantic localization ability of AMC. The codes and pretrained models are available at https://github.com/KevinLight831/AMC.