Few-shot learning aims to train models that can be generalized to novel classes with only a few samples. Recently, a line of works are proposed to enhance few-shot learning with accessible semantic information from class names. However, these works focus on improving existing modules such as visual prototypes and feature extractors of the standard few-shot learning framework. This limits the full potential use of semantic information. In this paper, we propose a novel few-shot learning framework that uses pre-trained language models based on contrastive learning. To address the challenge of alignment between visual features and textual embeddings obtained from text-based pre-trained language model, we carefully design the textual branch of our framework and introduce a metric module to generalize the cosine similarity. For better transferability, we let the metric module adapt to different few-shot tasks and adopt MAML to train the model via bi-level optimization. Moreover, we conduct extensive experiments on multiple benchmarks to demonstrate the effectiveness of our method.

本文提出了一种基于对比学习的新的 few-shot learning 框架，通过预训练语言模型解决视觉特征与文本嵌入之间的对齐问题，并引入度量模块来实现余弦相似度的泛化，通过双层优化结构中的 MAML 训练模型以提高可迁移性，此外，在多个基准测试上进行了大量实验证明我们方法的有效性。

FILM: 少样本图像分类如何从预训练语言模型中受益？