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图学学报 ›› 2025, Vol. 46 ›› Issue (3): 602-613.DOI: 10.11996/JG.j.2095-302X.2025030602

• 计算机图形学与虚拟现实 • 上一篇    下一篇

面向三维点云的平衡泛化和特化的细粒度分类网络

刘鸿硕1(), 白静1,2,3(), 晏浩1, 林淦1   

  1. 1.北方民族大学计算机科学与工程学院,宁夏 银川 750021
    2.国家民委图像图形智能处理实验室,宁夏 银川 750021
    3.六盘山实验室,宁夏 银川 750021
  • 收稿日期:2024-08-22 接受日期:2025-01-10 出版日期:2025-06-30 发布日期:2025-06-13
  • 通讯作者:白静(1982-),女,教授,博士。主要研究方向为CAD&CG、计算机视觉和机器学习等。E-mail:baijing@nun.edu.cn
  • 第一作者:刘鸿硕(2001-),男,硕士研究生。主要研究方向为三维点云细粒度分类。E-mail:1709671541@qq.com
  • 基金资助:
    国家自然科学基金(62162001);宁夏自然科学基金(2022AAC02041);宁夏优秀人才支持计划

BGS-Net: fine-grained classification networks with balanced generalization and specialization for 3D point clouds

LIU Hongshuo1(), BAI Jing1,2,3(), YAN Hao1, LIN Gan1   

  1. 1. School of Computer Science and Engineering, North Minzu University, Yinchuan Ningxia 750021, China
    2. The Key Laboratory of Images and Graphics Intelligent Processing of State Ethnic Affairs Commission, Yinchuan Ningxia 750021, China
    3. Liupanshan Laboratory, Yinchuan Ningxia 750021, China
  • Received:2024-08-22 Accepted:2025-01-10 Published:2025-06-30 Online:2025-06-13
  • Contact: BAI Jing (1982-), professor, Ph.D. Her main research interests cover CAD&CG, computer vision, and machine learning, etc. E-mail:baijing@nun.edu.cn
  • First author:LIU Hongshuo (2001-), master student. His main research interest covers 3D point cloud fine-grained classification. E-mail:1709671541@qq.com
  • Supported by:
    National Natural Science Foundation of China under Grant(62162001);Natural Science Foundation of Ningxia of China under Grant(2022AAC02041);Ningxia Excellent Talent Program

摘要:

随着三维理解和计算机视觉技术的快速发展,点云数据因其精确的几何描述和丰富的空间信息在研究中备受关注。特别是在智能交通等实际应用中,利用点云数据识别不同型号的车辆需要准确分类细微差异和特征,因此开展点云细粒度分类尤为重要。现有方法多侧重设计任务特化的网络,通过提取点云的局部判别性特征提升分类性能,但往往忽视模型的泛化能力,导致在不同场景或未见类别中的表现下降。此外,复杂环境下的噪声、遮挡或数据分布变化亦会削弱模型的特化能力。为解决上述问题,提出了一种两阶段点云细粒度分类网络BGS-Net,旨在平衡模型的泛化性与特化性。在第一阶段,采用掩码蒸馏自监督学习结合耦合掩码方法,为2个学生模型分配互补掩码,引导其从教师模型中学习独立的特征表示,从而增强泛化能力。第二阶段设计了平衡泛化与特化的训练策略,通过冻结一个编码器以保留通用特征,同时调优另一个编码器以提取点云的局部判别性特征,实现任务特化。实验结果表明,BGS-Net在细粒度分类、元类别分类、少样本分类及真实场景分类任务中均表现优异,显著优于现有方法,验证了在保持高泛化能力的同时实现任务特化的有效性。该方法为点云细粒度分类提供了新的研究思路,提升了模型在实际应用中的适用性和鲁棒性。

关键词: 点云理解, 自监督学习, 耦合掩码, 特征学习, 模型泛化

Abstract:

With the rapid advancement of 3D understanding and computer vision technologies, point cloud data have gained significant attention for their precise geometry and rich spatial information. In applications such as intelligent transportation, accurately classifying subtle differences in vehicle models is crucial, rendering fine-grained point cloud classification essential. However, existing methods focus heavily on task-specific networks that enhance classification by extracting local discriminative features, often neglecting the model’s generalization abilities. This resulted in decreased performance in diverse scenarios and unseen categories, especially in environments with noise, occlusions, or data distribution changes. To address these challenges, the balanced generalization specialization network (BGS-Net) was proposed as a two-stage framework that balanced generalization and specialization. In the first stage, BGS-Net employed mask distillation self-supervised learning with coupled masks to guide two student models in learning independent feature representations from a teacher model, thereby enhancing generalization. In the second stage, a balanced training strategy was implemented by freezing one encoder to preserve general features while fine-tuning the other encoder to extract locally discriminative features for task specialization. Experimental results demonstrated that BGS-Net significantly outperformed existing methods in fine-grained, meta-category, few-shot, and real-world classification tasks, thereby confirming its effectiveness in maintaining high generalization while achieving task specialization. This approach enhanced the applicability and robustness of point cloud classification in practical applications.

Key words: point cloud understanding, self-supervised learning, coupling mask, feature learning, model generalization

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