Most approaches in few-shot learning rely on costly annotated data related to the goal task domain during (pre-)training. Recently, unsupervised meta-learning methods have exchanged the annotation requirement for a reduction in few-shot classification performance. Simultaneously, in settings with realistic domain shift, common transfer learning has been shown to outperform supervised meta-learning. Building on these insights and on advances in self-supervised learning, we propose a transfer learning approach which constructs a metric embedding that clusters unlabeled prototypical samples and their augmentations closely together. This pre-trained embedding is a starting point for few-shot classification by summarizing class clusters and fine-tuning. We demonstrate that our self-supervised prototypical transfer learning approach ProtoTransfer outperforms state-of-the-art unsupervised meta-learning methods on few-shot tasks from the mini-ImageNet dataset. In few-shot experiments with domain shift, our approach even has comparable performance to supervised methods, but requires orders of magnitude fewer labels.

本文提出了一种自监督的原型传递学习方法 ProtoTransfer，旨在通过构建一个可以将未标记的样本和它们的增强聚类在一起的度量嵌入来预测少量标记数据的正确类别。我们在 mini-ImageNet 数据集上的少量样本分类任务中通过 ProtoTransfer 方法超越了最先进的无监督元学习方法。在存在领域偏移的少样本实验中，我们的方法甚至具有可比拟于监督方法的性能，但需要 orders of magnitude 较少的标签。

自监督原型转移学习用于少样本分类