Multi-Label Zero-Shot Learning via Concept Embedding
This addresses the problem of multi-label classification with unseen labels for applications like multimedia tagging, though it appears incremental as it extends single-label ZSL methods.
The paper tackles multi-label zero-shot learning by proposing a concept embedding approach that maps instance features to an embedding space, enabling classification of unseen labels and handling out-of-vocabulary labels without retraining. Experimental results show it outperforms a state-of-the-art model on images and music tracks.
Zero Shot Learning (ZSL) enables a learning model to classify instances of an unseen class during training. While most research in ZSL focuses on single-label classification, few studies have been done in multi-label ZSL, where an instance is associated with a set of labels simultaneously, due to the difficulty in modeling complex semantics conveyed by a set of labels. In this paper, we propose a novel approach to multi-label ZSL via concept embedding learned from collections of public users' annotations of multimedia. Thanks to concept embedding, multi-label ZSL can be done by efficiently mapping an instance input features onto the concept embedding space in a similar manner used in single-label ZSL. Moreover, our semantic learning model is capable of embedding an out-of-vocabulary label by inferring its meaning from its co-occurring labels. Thus, our approach allows both seen and unseen labels during the concept embedding learning to be used in the aforementioned instance mapping, which makes multi-label ZSL more flexible and suitable for real applications. Experimental results of multi-label ZSL on images and music tracks suggest that our approach outperforms a state-of-the-art multi-label ZSL model and can deal with a scenario involving out-of-vocabulary labels without re-training the semantics learning model.