• 中国计算机学会会刊
  • 中国科技核心期刊
  • 中文核心期刊

计算机工程与科学 ›› 2025, Vol. 47 ›› Issue (7): 1285-1294.

• 图形与图像 • 上一篇    下一篇

一种类别感知的半监督知识蒸馏长尾分类模型

纪磊,李希,徐大宏,刘宏,郭建平   

  1. (湖南师范大学信息科学与工程学院,湖南 长沙 410081)
  • 收稿日期:2024-02-27 修回日期:2024-05-02 出版日期:2025-07-25 发布日期:2025-08-25

A category-aware semi-supervised knowledge distillation medel for long-tailed classification

JI Lei,LI Xi,XU Dahong,LIU Hong,GUO Jianping   

  1. (College of Information Science and Engineering,Hunan Normal University,Changsha 410081,China)
  • Received:2024-02-27 Revised:2024-05-02 Online:2025-07-25 Published:2025-08-25

摘要: 在基于分类的模式识别任务中,训练过程需要处理大量不同类别的样本。在实际应用中,这些样本具有显著的长尾分布特性,给模式识别任务带来了巨大挑战。长尾分布带来的挑战主要体现在2个方面:特征空间不平衡以及难以关注长尾区域的困难样本。针对这2个方面,提出了一种类别感知的半监督知识蒸馏模型,该模型包含了2个核心组成部分:平衡的半监督知识蒸馏和平衡的类别感知学习。前者利用半监督知识蒸馏,使特征空间更加平衡;后者融合类别感知的扩张损失函数与困难样本延迟学习激活式损失函数,提升了分类器的性能,并增强对困难样本的关注度。所有实验在5个基线数据集上进行,包括CIFAR10-LT,CIFAR-100-LT,ImageNet-LT,iNaturalist2018和Places-LT,其中在ImageNet-LT上,所提模型达到了57.5%的Top-1准确率,优于其他的模型。

关键词: 半监督, 类别感知, 长尾分类

Abstract: In classification-based pattern recognition tasks,the training process requires handling a large number of category samples.In practice,these samples exhibit a significant long-tailed distribution characteristic,posing substantial challenges for such tasks.The challenges brought by long-tailed distribution mainly manifest in two aspects:imbalanced feature space,and difficulty in focusing on hard samples in the tail regions.To address these issues,a category-aware semi-supervised knowledge distillation model is proposed,which comprises two core components:balanced semi-supervised knowledge distillation and balanced category-aware learning.The former employs semi-supervised knowledge distillation to achieve a more balanced feature space.The latter integrates a category-aware margin loss function with a delayed hard sample learning activation loss function,improving classifier performance and enhancing focus on hard samples.All experiments were conducted on five benchmark datasets,including CIFAR10-LT,CIFAR-100-LT,ImageNet-LT,iNaturalist2018,and Places-LT.Notably,on ImageNet-LT,the proposed model achieved a Top-1 accuracy of 57.5%,outperforming other models.

Key words: semi-supervised, category-aware, long-tailed classification