Zero-shot learning (ZSL) aims to predict unseen classes whose samples have never appeared during training. One of the most effective and widely used semantic information for zero-shot image classification are attributes which are annotations for class-level visual characteristics. However, the current methods often fail to discriminate those subtle visual distinctions between images due to not only the shortage of fine-grained annotations, but also the attribute imbalance and co-occurrence. In this paper, we present a transformer-based end-to-end ZSL method named DUET, which integrates latent semantic knowledge from the pre-trained language models (PLMs) via a self-supervised multi-modal learning paradigm. Specifically, we (1) developed a cross-modal semantic grounding network to investigate the model's capability of disentangling semantic attributes from the images; (2) applied an attribute-level contrastive learning strategy to further enhance the model's discrimination on fine-grained visual characteristics against the attribute co-occurrence and imbalance; (3) proposed a multi-task learning policy for considering multi-model objectives. We find that our DUET can achieve state-of-the-art performance on three standard ZSL benchmarks and a knowledge graph equipped ZSL benchmark. Its components are effective and its predictions are interpretable.
翻译:零样本学习(ZSL)旨在预测训练过程中从未出现样本的未见类别。属性作为类别级视觉特征的标注,是零样本图像分类中最有效且广泛使用的语义信息之一。然而,现有方法常因细粒度标注不足、属性不平衡及共现问题,难以区分图像间细微的视觉差异。本文提出一种基于Transformer的端到端ZSL方法DUET,通过自监督多模态学习范式,从预训练语言模型(PLMs)中整合潜在语义知识。具体而言,我们:(1)构建跨模态语义锚定网络,探究模型从图像中解耦语义属性的能力;(2)应用属性级对比学习策略,进一步增强模型对细粒度视觉特征的判别能力,以应对属性共现与不平衡问题;(3)提出多任务学习策略以整合多模型目标。实验表明,DUET在三个标准ZSL基准测试及一个知识图谱增强的ZSL基准测试上均实现了最优性能,其各组件有效且预测结果具有可解释性。