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arXiv 2307.12917cs.CVcs.AI

用于无监督行人重识别的分层骨架元原型对比学习与困难骨架挖掘

Hierarchical Skeleton Meta-Prototype Contrastive Learning with Hard Skeleton Mining for Unsupervised Person Re-Identification

Nanyang Technological University(南洋理工大学);The University of British Columbia(不列颠哥伦比亚大学)

Haocong Rao, Cyril Leung, Chunyan Miao

AI总结:

本文提出无监督分层骨架元原型对比学习方法Hi-MPC,结合困难骨架挖掘HSM,通过关节、部件、肢体分层建模与元原型一致性学习,在多个数据集上超越现有骨架行人重识别方法。

摘要:

随着深度传感器和深度学习的快速发展,基于骨架的行人重识别(re-ID)模型近年来取得了显著进展并展现出诸多优势。现有大多数方法在假设各骨架重要性相等的前提下,从身体关节中学习单层骨架特征,但通常缺乏从肢体层级等更具全局身体模式的层级中利用更具信息量骨架特征的能力。这些方法对标签的依赖也限制了它们在学习更通用骨架表示方面的灵活性。本文提出了一种通用的无监督分层骨架元原型对比学习(Hi-MPC)方法,并结合困难骨架挖掘(HSM),用于基于无标签3D骨架的行人重识别。首先,我们构建骨架的分层表示,从身体关节、部件和肢体三个层级建模由粗到细的身体与运动特征。然后,提出一种分层元原型对比学习模型,对不同层级骨架中最具代表性的骨架特征(“原型”)进行聚类和对比。通过将原始原型经多种同质变换转换为元原型,我们引导模型学习原型的内在一致性,从而捕获更有效的骨架特征用于行人重识别。此外,我们设计了一种困难骨架挖掘机制,自适应地推断每个骨架的信息重要性,从而聚焦于更困难的骨架,以学习更具判别力的骨架表示。在五个数据集上的广泛评估表明,我们的方法优于多种最先进的基于骨架的方法。我们进一步展示了该方法在跨视角行人重识别以及基于估计骨架的RGB场景中的通用适用性。

英文摘要:

With rapid advancements in depth sensors and deep learning, skeleton-based person re-identification (re-ID) models have recently achieved remarkable progress with many advantages. Most existing solutions learn single-level skeleton features from body joints with the assumption of equal skeleton importance, while they typically lack the ability to exploit more informative skeleton features from various levels such as limb level with more global body patterns. The label dependency of these methods also limits their flexibility in learning more general skeleton representations. This paper proposes a generic unsupervised Hierarchical skeleton Meta-Prototype Contrastive learning (Hi-MPC) approach with Hard Skeleton Mining (HSM) for person re-ID with unlabeled 3D skeletons. Firstly, we construct hierarchical representations of skeletons to model coarse-to-fine body and motion features from the levels of body joints, components, and limbs. Then a hierarchical meta-prototype contrastive learning model is proposed to cluster and contrast the most typical skeleton features ("prototypes") from different-level skeletons. By converting original prototypes into meta-prototypes with multiple homogeneous transformations, we induce the model to learn the inherent consistency of prototypes to capture more effective skeleton features for person re-ID. Furthermore, we devise a hard skeleton mining mechanism to adaptively infer the informative importance of each skeleton, so as to focus on harder skeletons to learn more discriminative skeleton representations. Extensive evaluations on five datasets demonstrate that our approach outperforms a wide variety of state-of-the-art skeleton-based methods. We further show the general applicability of our method to cross-view person re-ID and RGB-based scenarios with estimated skeletons.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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