Prompt Expending for Single Positive Multi-Label Learning with Global Unannotated Categories.

Multi-label learning (MLL) learns from samples associated with multiple labels, where it is expensive and time consuming to provide detailed annotation for each sample in real-world datasets. To deal with this challenge, single positive multi-label learning (SPML) has been studied in recent years. In SPML, each sample is annotated with only one positive label, which is much easier and less costly. However, in many real-world scenarios, single positive labels may have global unannotated categories (GUCs) in annotation process, which exist in the label space but do not serve as single positive label for any samples. Unfortunately, previous SPML approaches are less applicable to classify GUCs due to the absence of supervised information. To solve this problem, we propose a novel prompt expanding framework that leverages a large-scale pretrained vision and language model called the Recognize Anything Model (RAM) to offer supervision signals for GUCs. Specifically, we first provide a simple but effective strategy to generate reliable pseudo-labels for GUCs by utilizing zero-shot predictions of RAM. Subsequently, we introduce additional prompts from a large common category list and fuse them by learnable weighting factors, which expends the semantic representation of GUCs. Experiments show that our method achieves state-of-the-art results on all four benchmarks. The code to reproduce the experiments is at: https://github.com/yingpenga/VLSPE