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arXiv 1704.02206cs.CV
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DeepCoder:用于自动面部动作编码的半参数变分自编码器

DeepCoder: Semi-parametric Variational Autoencoders for Automatic Facial Action Coding

Dieu Linh Tran, Robert Walecki, Ognjen Rudovic, Stefanos Eleftheriadis, Bjørn Schuller, Maja Pantic

摘要:

人脸在其表示中表现出固有的层次结构(即,整体面部表情可以通过一组面部动作单元(AU)及其强度来编码)。变分(深度)自动编码器(VAE)在从大量图像数据中无监督地提取分层潜在表示方面表现出很好的效果,同时对噪声和其他不期望的伪影具有鲁棒性。潜在地,这使得VAE成为学习用于AU强度估计的面部特征的合适方法。然而,大多数现有的基于VAE的方法应用从编码特征中单独学习的分类器。相比之下,非参数(概率)方法,如高斯过程(GP),通常优于其参数对应物,但不能轻松处理大量数据。为此,我们提出了一种新的VAE半参数建模框架,名为DeepCoder,它结合了参数(卷积)和非参数(序数GP)VAE的建模能力,用于联合学习(1)任务层次结构中多个级别的潜在表示1,以及(2)多个序数输出的分类。我们在AU强度估计的基准数据集上显示,所提出的DeepCoder优于最先进的方法以及相关的VAE和深度学习模型。

英文摘要:

Human face exhibits an inherent hierarchy in its representations (i.e., holistic facial expressions can be encoded via a set of facial action units (AUs) and their intensity). Variational (deep) auto-encoders (VAE) have shown great results in unsupervised extraction of hierarchical latent representations from large amounts of image data, while being robust to noise and other undesired artifacts. Potentially, this makes VAEs a suitable approach for learning facial features for AU intensity estimation. Yet, most existing VAE-based methods apply classifiers learned separately from the encoded features. By contrast, the non-parametric (probabilistic) approaches, such as Gaussian Processes (GPs), typically outperform their parametric counterparts, but cannot deal easily with large amounts of data. To this end, we propose a novel VAE semi-parametric modeling framework, named DeepCoder, which combines the modeling power of parametric (convolutional) and nonparametric (ordinal GPs) VAEs, for joint learning of (1) latent representations at multiple levels in a task hierarchy1, and (2) classification of multiple ordinal outputs. We show on benchmark datasets for AU intensity estimation that the proposed DeepCoder outperforms the state-of-the-art approaches, and related VAEs and deep learning models.

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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