Walsh Reece, Osman Islam, Shehata Mohamed S
IEEE Trans Image Process. 2023;32:4907-4920. doi: 10.1109/TIP.2023.3306916. Epub 2023 Sep 4.
In few-shot classification, performing well on a testing dataset is a challenging task due to the restricted amount of labelled data available and the unknown distribution. Many previously proposed techniques rely on prototypical representations of the support set in order to classify a query set. Although this approach works well with a large, in-domain support set, accuracy suffers when transitioning to an out-of-domain setting, especially when using small support sets. To address out-of-domain performance degradation with small support sets, we propose Masked Embedding Modeling for Few-Shot Learning (MEM-FS), a novel, self-supervised, generative technique that reinforces few-shot-classification accuracy for a prototypical backbone model. MEM-FS leverages the data completion capabilities of a masked autoencoder to expand a given embedded support set. To further increase out-of-domain performance, we also introduce Rapid Domain Adjustment (RDA), a novel, self-supervised process for quickly conditioning MEM-FS to a new domain. We show that masked support embeddings generated by MEM-FS+RDA can significantly improve backbone performance on both out-of-domain and in-domain datasets. Our experiments demonstrate that applying the proposed technique to an inductive classifier achieves state-of-the-art performance on mini-imagenet, the CVPR L2ID Classification Challenge, and a newly proposed dataset, IKEA-FS. We provide code for this work at https://github.com/Brikwerk/MEM-FS.
在少样本分类中,由于可用的标记数据量有限且分布未知,在测试数据集上取得良好性能是一项具有挑战性的任务。许多先前提出的技术依赖于支持集的原型表示来对查询集进行分类。尽管这种方法在大型的、领域内的支持集上效果良好,但在过渡到领域外设置时,准确率会受到影响,尤其是在使用小型支持集时。为了解决小型支持集在领域外的性能下降问题,我们提出了用于少样本学习的掩码嵌入建模(MEM-FS),这是一种新颖的、自监督的生成技术,可提高原型主干模型的少样本分类准确率。MEM-FS利用掩码自动编码器的数据补全能力来扩展给定的嵌入支持集。为了进一步提高领域外性能,我们还引入了快速域调整(RDA),这是一种新颖的自监督过程,可以快速使MEM-FS适应新领域。我们表明,由MEM-FS+RDA生成掩码支持嵌入可以显著提高主干模型在领域外和领域内数据集上的性能。我们的实验表明,将所提出的技术应用于归纳分类器可在mini-imagenet、CVPR L2ID分类挑战赛和新提出的数据集IKEA-FS上实现当前最优性能。我们在https://github.com/Brikwerk/MEM-FS上提供了这项工作的代码。