arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2403.03400cs.CV

面向面部动作单元检测的个体无关表征对比学习

Contrastive Learning of Person-independent Representations for Facial Action Unit Detection

School of Computer Science and Engineering, Nanjing University of Science and Technology(南京理工大学计算机科学与工程学院);University of Chinese Academy of Sciences(中国科学院大学);Peng Cheng Laboratory(鹏城实验室)

Yong Li, Shiguang Shan

AI总结:

针对面部AU检测标注不足的问题,提出结合时序对比学习与跨身份重建的自监督方法,学习个体无关AU表征,在三个公开数据集上性能优于同类方法,缩小了与监督方法的差距。

摘要:

面部动作单元(AU)检测旨在对人脸图像中存在的AU进行分类,长期以来一直受限于AU标注不足的问题。在本文中,我们旨在通过对比学习范式从大量无标注人脸视频中学习AU表征,以缓解这一数据稀缺问题。我们从两方面构建自监督AU表征学习的信号:(1)AU表征应在短视频片段内具备帧级判别性;(2)来自不同身份但呈现相似面部AU的人脸帧应具有一致的AU表征。为实现这些目标,我们提出在视频片段内对比学习AU表征,并设计了跨身份重建机制以学习个体无关表征。具体而言,我们采用基于边际的时序对比学习范式,来感知由连续输入人脸帧组成的片段内的时序AU连贯性与演化特征。此外,跨身份重建机制有助于推动来自不同身份但呈现相似AU的人脸在潜在嵌入空间中相互靠近。在三个公开AU数据集上的实验结果表明,所学习的AU表征对AU检测具有判别性。我们的方法优于其他对比学习方法,并且显著缩小了自监督与监督式AU检测方法之间的性能差距。

英文摘要:

Facial action unit (AU) detection, aiming to classify AU present in the facial image, has long suffered from insufficient AU annotations. In this paper, we aim to mitigate this data scarcity issue by learning AU representations from a large number of unlabelled facial videos in a contrastive learning paradigm. We formulate the self-supervised AU representation learning signals in two-fold: (1) AU representation should be frame-wisely discriminative within a short video clip; (2) Facial frames sampled from different identities but show analogous facial AUs should have consistent AU representations. As to achieve these goals, we propose to contrastively learn the AU representation within a video clip and devise a cross-identity reconstruction mechanism to learn the person-independent representations. Specially, we adopt a margin-based temporal contrastive learning paradigm to perceive the temporal AU coherence and evolution characteristics within a clip that consists of consecutive input facial frames. Moreover, the cross-identity reconstruction mechanism facilitates pushing the faces from different identities but show analogous AUs close in the latent embedding space. Experimental results on three public AU datasets demonstrate that the learned AU representation is discriminative for AU detection. Our method outperforms other contrastive learning methods and significantly closes the performance gap between the self-supervised and supervised AU detection approaches.

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。

↑