Real-world data often exhibits a long-tailed distribution, in which head classes occupy most of the data, while tail classes only have very few samples. Models trained on long-tailed datasets have poor adaptability to tail classes and the decision boundaries are ambiguous. Therefore, in this paper, we propose a simple yet effective model, named Dual-Branch Long-Tailed Recognition (DB-LTR), which includes an imbalanced learning branch and a Contrastive Learning Branch (CoLB). The imbalanced learning branch, which consists of a shared backbone and a linear classifier, leverages common imbalanced learning approaches to tackle the data imbalance issue. In CoLB, we learn a prototype for each tail class, and calculate an inter-branch contrastive loss, an intra-branch contrastive loss and a metric loss. CoLB can improve the capability of the model in adapting to tail classes and assist the imbalanced learning branch to learn a well-represented feature space and discriminative decision boundary. Extensive experiments on three long-tailed benchmark datasets, i.e., CIFAR100-LT, ImageNet-LT and Places-LT, show that our DB-LTR is competitive and superior to the comparative methods.

本文介绍了一种名为双分支长尾识别（DB-LTR）的简单而有效的模型，它包括一个不平衡学习分支和一个对比学习分支（CoLB），通过利用常见的不平衡学习方法来解决数据不平衡问题，并通过对比学习分支来改善模型对尾部类别的适应能力，并学习出一个具有很好表现特征空间和有区分度的决策边界。在CIFAR100-LT、ImageNet-LT和Places-LT三个长尾基准数据集上的大量实验证明，DB-LTR相比比较方法具有竞争力且卓越。

一种用于长尾识别的具有互分支和内分支对比损失的双分支模型