论文标题
小精灵:长尾分类的早期效果框架
ELF: An Early-Exiting Framework for Long-Tailed Classification
论文作者
论文摘要
自然世界经常遵循长尾数据的数据分布,其中只有几个类说明了大多数示例。这种长尾尾会导致分类器过度擅长多数级别。为了减轻这种情况,先前的解决方案通常采用类重新平衡策略,例如数据重新采样和损失重塑。但是,通过平等地对待一类中的每个示例,这些方法无法说明示例硬度的重要概念,即,在每个类中,一些示例比其他示例更容易分类。为了将这种硬度的概念纳入学习过程,我们提出了早期效果框架(ELF)。在培训期间,精灵通过附加在骨干网络上的辅助分支来学习早期的简单示例。这提供了双重好处 - (1)神经网络越来越重点介绍了辛苦的例子,因为它们会对整体网络损失做出更大的贡献; (2)它释放了其他模型能力来区分困难的例子。在两个大规模数据集(ImageNet LT和Inaturist'18)上进行的实验结果表明,精灵可以将最新准确性提高3%以上。这带来了将高达20%的推理时间拖鞋降低的额外好处。小精灵与先前的工作相辅相成,并且可以自然地与各种现有方法集成,以应对长尾分布的挑战。
The natural world often follows a long-tailed data distribution where only a few classes account for most of the examples. This long-tail causes classifiers to overfit to the majority class. To mitigate this, prior solutions commonly adopt class rebalancing strategies such as data resampling and loss reshaping. However, by treating each example within a class equally, these methods fail to account for the important notion of example hardness, i.e., within each class some examples are easier to classify than others. To incorporate this notion of hardness into the learning process, we propose the EarLy-exiting Framework(ELF). During training, ELF learns to early-exit easy examples through auxiliary branches attached to a backbone network. This offers a dual benefit-(1) the neural network increasingly focuses on hard examples, since they contribute more to the overall network loss; and (2) it frees up additional model capacity to distinguish difficult examples. Experimental results on two large-scale datasets, ImageNet LT and iNaturalist'18, demonstrate that ELF can improve state-of-the-art accuracy by more than 3 percent. This comes with the additional benefit of reducing up to 20 percent of inference time FLOPS. ELF is complementary to prior work and can naturally integrate with a variety of existing methods to tackle the challenge of long-tailed distributions.