  Recently, zero-shot multi-label classification has garnered considerable
attention for its capacity to operate predictions on unseen labels without
human annotations. Nevertheless, prevailing approaches often use seen classes
as imperfect proxies for unseen ones, resulting in suboptimal performance.
Drawing inspiration from the success of text-to-image generation models in
producing realistic images, we propose an innovative solution: generating
synthetic data to construct a training set explicitly tailored for proxyless
training on unseen labels. Our approach introduces a novel image generation
framework that produces multi-label synthetic images of unseen classes for
classifier training. To enhance diversity in the generated images, we leverage
a pre-trained large language model to generate diverse prompts. Employing a
pre-trained multi-modal CLIP model as a discriminator, we assess whether the
generated images accurately represent the target classes. This enables
automatic filtering of inaccurately generated images, preserving classifier
accuracy. To refine text prompts for more precise and effective multi-label
object generation, we introduce a CLIP score-based discriminative loss to
fine-tune the text encoder in the diffusion model. Additionally, to enhance
visual features on the target task while maintaining the generalization of
original features and mitigating catastrophic forgetting resulting from
fine-tuning the entire visual encoder, we propose a feature fusion module
inspired by transformer attention mechanisms. This module aids in capturing
global dependencies between multiple objects more effectively. Extensive
experimental results validate the effectiveness of our approach, demonstrating
significant improvements over state-of-the-art methods.
