论文标题
用粗标签的细粒角对比度学习
Fine-grained Angular Contrastive Learning with Coarse Labels
论文作者
论文摘要
很少有射击的学习方法提供优化的预训练技术,以便更轻松地使用一个或几个示例将模型改编为新类(在培训期间看不见)。这种对看不见类的适应性对于许多实用的应用程序尤为重要,因为预培训的标签空间不能保持固定以进行有效使用,并且该模型需要“专业化”才能即时支持新类别。一个特别有趣的场景,本质上被少量文献所忽略了,是粗到少量射击(C2F),其中训练类(例如动物)比目标(测试)类(例如品种)要比目标(测试)类(例如品种)要大得多。 C2FS的一个非常实用的例子是,目标类是培训类的子类时。从直觉上讲,这尤其具有挑战性,因为(常规和少数)受监督的预训练倾向于学会忽略阶级内变异性,这对于分离子类是必不可少的。在本文中,我们介绍了一个新颖的“角度归一化”模块,该模块允许有效地结合受监督和自我监管的对比预训练,以应对所提出的C2FS任务,在对多个基线和数据集的广泛研究中显示出显着的增长。我们希望这项工作将有助于对C2FS分类的这一新,具有挑战性且非常实用的主题的未来研究铺平道路。
Few-shot learning methods offer pre-training techniques optimized for easier later adaptation of the model to new classes (unseen during training) using one or a few examples. This adaptivity to unseen classes is especially important for many practical applications where the pre-trained label space cannot remain fixed for effective use and the model needs to be "specialized" to support new categories on the fly. One particularly interesting scenario, essentially overlooked by the few-shot literature, is Coarse-to-Fine Few-Shot (C2FS), where the training classes (e.g. animals) are of much `coarser granularity' than the target (test) classes (e.g. breeds). A very practical example of C2FS is when the target classes are sub-classes of the training classes. Intuitively, it is especially challenging as (both regular and few-shot) supervised pre-training tends to learn to ignore intra-class variability which is essential for separating sub-classes. In this paper, we introduce a novel 'Angular normalization' module that allows to effectively combine supervised and self-supervised contrastive pre-training to approach the proposed C2FS task, demonstrating significant gains in a broad study over multiple baselines and datasets. We hope that this work will help to pave the way for future research on this new, challenging, and very practical topic of C2FS classification.