Overcoming Catastrophic Forgetting for Multi-Label Class-Incremental Learning

Despite the recent progress of class-incremental learning (CIL) methods, their capabilities in real-world scenarios such as multi-label settings remain unexplored. This paper focuses on a more practical CIL problem named multi-label class-incremental learning (MLCIL). MLCIL requires the vision models to overcome catastrophic forgetting of old knowledge while learning new classes from multi-label samples. Direct application of existing CIL methods to MLCIL leads to label absence, representative sample selection, and feature dilution problems. To address these problems, we present a novel AdaPtive Pseudo-Label-drivEn (APPLE) framework consisting of three components. First, the adaptive pseudo-label strategy is proposed to solve the label absence problem, which leverages the old model to annotate old classes for new samples. Second, a cluster sampling strategy is proposed to obtain more diverse samples to alleviate catastrophic forgetting under the MLCIL setting better. Finally, a class attention decoder is designed to mitigate the object feature dilution problem in multi-label samples. The extensive experiments on PASCAL VOC 2007 and MS-COCO demonstrate that our proposed method significantly outperforms other representative state-of-the-art CIL methods.