19 research outputs found
DeepCoder: Semi-parametric Variational Autoencoders for Automatic Facial Action Coding
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.Comment: ICCV 2017 - accepte
Unsupervised Learning Facial Parameter Regressor for Action Unit Intensity Estimation via Differentiable Renderer
Facial action unit (AU) intensity is an index to describe all visually
discernible facial movements. Most existing methods learn intensity estimator
with limited AU data, while they lack generalization ability out of the
dataset. In this paper, we present a framework to predict the facial parameters
(including identity parameters and AU parameters) based on a bone-driven face
model (BDFM) under different views. The proposed framework consists of a
feature extractor, a generator, and a facial parameter regressor. The regressor
can fit the physical meaning parameters of the BDFM from a single face image
with the help of the generator, which maps the facial parameters to the
game-face images as a differentiable renderer. Besides, identity loss, loopback
loss, and adversarial loss can improve the regressive results. Quantitative
evaluations are performed on two public databases BP4D and DISFA, which
demonstrates that the proposed method can achieve comparable or better
performance than the state-of-the-art methods. What's more, the qualitative
results also demonstrate the validity of our method in the wild
Deep Structure Inference Network for Facial Action Unit Recognition
Facial expressions are combinations of basic components called Action Units
(AU). Recognizing AUs is key for developing general facial expression analysis.
In recent years, most efforts in automatic AU recognition have been dedicated
to learning combinations of local features and to exploiting correlations
between Action Units. In this paper, we propose a deep neural architecture that
tackles both problems by combining learned local and global features in its
initial stages and replicating a message passing algorithm between classes
similar to a graphical model inference approach in later stages. We show that
by training the model end-to-end with increased supervision we improve
state-of-the-art by 5.3% and 8.2% performance on BP4D and DISFA datasets,
respectively