OpenAVE: Moving towards Open Set Audio-Visual Event Localization

Audio-Visual Event (AVE) Localization aims to identify and classify video segments that are both audible and visible, a field that has seen substantial progress in recent years. Existing methods operate under a closed-set assumption and struggle to recognize unknown events in open-world scenarios. To better adapt to real-life applications, we introduce the Open Set Audio-Visual Event Localization task and propose a novel and effective network called OpenAVE based on evidential deep learning. To the best of our knowledge, this is the first effort to address this challenge. Our approach encompasses deep evidential AVE classification and event-relevant prediction, targeting the nuanced demands of open-set environments. The deep evidential AVE classification manages event classification uncertainty by extracting class evidence from segment-specific representations enriched with multi-scale context. To effectively distinguish between unknown events and background segments, event-relevant prediction utilizes positive-unlabeled learning. Futhermore, a learnable Gaussian-prior prediction branch is adopted to enhance the performance of event-relevant prediction. Experimental results demonstrate that OpenAVE significantly outperforms state-of-the-art models on the Audio-Visual Event dataset, confirming the effectiveness of our proposed method.