Few-shot class incremental learning -- the problem of updating a trained classifier to discriminate among an expanded set of classes with limited labeled data -- is a key challenge for machine learning systems deployed in non-stationary environments. Existing approaches to the problem rely on complex model architectures and training procedures that are difficult to tune and re-use. In this paper, we present an extremely simple approach that enables the use of ordinary logistic regression classifiers for few-shot incremental learning. The key to this approach is a new family of subspace regularization schemes that encourage weight vectors for new classes to lie close to the subspace spanned by the weights of existing classes. When combined with pretrained convolutional feature extractors, logistic regression models trained with subspace regularization outperform specialized, state-of-the-art approaches to few-shot incremental image classification by up to 22% on the miniImageNet dataset. Because of its simplicity, subspace regularization can be straightforwardly extended to incorporate additional background information about the new classes (including class names and descriptions specified in natural language); these further improve accuracy by up to 2%. Our results show that simple geometric regularization of class representations offers an effective tool for continual learning.

本文提出了一种简单的机器学习方法，通过采用特定的子空间正则化方案，让新增类别的权重向量与现有类别的权重向量所构成的子空间尽量接近，实现了使用普通逻辑回归分类器进行少样本类别增量学习的目的，该方法在miniImageNet数据集上优于当前的前沿方法22％，并可以直接扩展以包含有关新类的其他信息，进一步提高2％的准确性。因此，简单的几何正则化类表示法是持续学习的有效工具。

Few-Shot 类增量学习的子空间正则化器