Recently how to introduce large amounts of unlabeled facial images in the
wild into supervised Facial Action Unit (AU) detection frameworks has become a
challenging problem. In this paper, we propose a new AU detection framework
where multi-task learning is introduced to jointly learn AU domain separation
and reconstruction and facial landmark detection by sharing the parameters of
homostructural facial extraction modules. In addition, we propose a new feature
alignment scheme based on contrastive learning by simple projectors and an
improved contrastive loss, which adds four additional intermediate supervisors
to promote the feature reconstruction process. Experimental results on two
benchmarks demonstrate our superiority against the state-of-the-art methods for
AU detection in the wild.

提出了一种新的 AU 检测框架，其中引入了多任务学习，通过共享同构面部提取模块的参数来共同学习 AU 领域分离和重建以及面部标志检测。此外，提出了一种基于对比学习和改进的对比损失的新特征对齐方案，通过添加四个中间监督器来促进特征重建过程。在两个基准测试上的实验结果表明，对于野外 AU 检测，我们优于现有的方法。