2,573 research outputs found
Analyzing Input and Output Representations for Speech-Driven Gesture Generation
This paper presents a novel framework for automatic speech-driven gesture
generation, applicable to human-agent interaction including both virtual agents
and robots. Specifically, we extend recent deep-learning-based, data-driven
methods for speech-driven gesture generation by incorporating representation
learning. Our model takes speech as input and produces gestures as output, in
the form of a sequence of 3D coordinates. Our approach consists of two steps.
First, we learn a lower-dimensional representation of human motion using a
denoising autoencoder neural network, consisting of a motion encoder MotionE
and a motion decoder MotionD. The learned representation preserves the most
important aspects of the human pose variation while removing less relevant
variation. Second, we train a novel encoder network SpeechE to map from speech
to a corresponding motion representation with reduced dimensionality. At test
time, the speech encoder and the motion decoder networks are combined: SpeechE
predicts motion representations based on a given speech signal and MotionD then
decodes these representations to produce motion sequences. We evaluate
different representation sizes in order to find the most effective
dimensionality for the representation. We also evaluate the effects of using
different speech features as input to the model. We find that mel-frequency
cepstral coefficients (MFCCs), alone or combined with prosodic features,
perform the best. The results of a subsequent user study confirm the benefits
of the representation learning.Comment: Accepted at IVA '19. Shorter version published at AAMAS '19. The code
is available at
https://github.com/GestureGeneration/Speech_driven_gesture_generation_with_autoencode
Capture, Learning, and Synthesis of 3D Speaking Styles
Audio-driven 3D facial animation has been widely explored, but achieving
realistic, human-like performance is still unsolved. This is due to the lack of
available 3D datasets, models, and standard evaluation metrics. To address
this, we introduce a unique 4D face dataset with about 29 minutes of 4D scans
captured at 60 fps and synchronized audio from 12 speakers. We then train a
neural network on our dataset that factors identity from facial motion. The
learned model, VOCA (Voice Operated Character Animation) takes any speech
signal as input - even speech in languages other than English - and
realistically animates a wide range of adult faces. Conditioning on subject
labels during training allows the model to learn a variety of realistic
speaking styles. VOCA also provides animator controls to alter speaking style,
identity-dependent facial shape, and pose (i.e. head, jaw, and eyeball
rotations) during animation. To our knowledge, VOCA is the only realistic 3D
facial animation model that is readily applicable to unseen subjects without
retargeting. This makes VOCA suitable for tasks like in-game video, virtual
reality avatars, or any scenario in which the speaker, speech, or language is
not known in advance. We make the dataset and model available for research
purposes at http://voca.is.tue.mpg.de.Comment: To appear in CVPR 201
The Effect of Real-Time Constraints on Automatic Speech Animation
Machine learning has previously been applied successfully to speech-driven facial animation. To account for carry-over and anticipatory coarticulation a common approach is to predict the facial pose using a symmetric window of acoustic speech that includes both past and future context. Using future context limits this approach for animating the faces of characters in real-time and networked applications, such as online gaming. An acceptable latency for conversational speech is 200ms and typically network transmission times will consume a significant part of this. Consequently, we consider asymmetric windows by investigating the extent to which decreasing the future context effects the quality of predicted animation using both deep neural networks (DNNs) and bi-directional LSTM recurrent neural networks (BiLSTMs). Specifically we investigate future contexts from 170ms (fully-symmetric) to 0ms (fullyasymmetric
Speech-driven Animation with Meaningful Behaviors
Conversational agents (CAs) play an important role in human computer
interaction. Creating believable movements for CAs is challenging, since the
movements have to be meaningful and natural, reflecting the coupling between
gestures and speech. Studies in the past have mainly relied on rule-based or
data-driven approaches. Rule-based methods focus on creating meaningful
behaviors conveying the underlying message, but the gestures cannot be easily
synchronized with speech. Data-driven approaches, especially speech-driven
models, can capture the relationship between speech and gestures. However, they
create behaviors disregarding the meaning of the message. This study proposes
to bridge the gap between these two approaches overcoming their limitations.
The approach builds a dynamic Bayesian network (DBN), where a discrete variable
is added to constrain the behaviors on the underlying constraint. The study
implements and evaluates the approach with two constraints: discourse functions
and prototypical behaviors. By constraining on the discourse functions (e.g.,
questions), the model learns the characteristic behaviors associated with a
given discourse class learning the rules from the data. By constraining on
prototypical behaviors (e.g., head nods), the approach can be embedded in a
rule-based system as a behavior realizer creating trajectories that are timely
synchronized with speech. The study proposes a DBN structure and a training
approach that (1) models the cause-effect relationship between the constraint
and the gestures, (2) initializes the state configuration models increasing the
range of the generated behaviors, and (3) captures the differences in the
behaviors across constraints by enforcing sparse transitions between shared and
exclusive states per constraint. Objective and subjective evaluations
demonstrate the benefits of the proposed approach over an unconstrained model.Comment: 13 pages, 12 figures, 5 table
Continuous Analysis of Affect from Voice and Face
Human affective behavior is multimodal, continuous and complex. Despite major advances within the affective computing research field, modeling, analyzing, interpreting and responding to human affective behavior still remains a challenge for automated systems as affect and emotions are complex constructs, with fuzzy boundaries and with substantial individual differences in expression and experience [7]. Therefore, affective and behavioral computing researchers have recently invested increased effort in exploring how to best model, analyze and interpret the subtlety, complexity and continuity (represented along a continuum e.g., from −1 to +1) of affective behavior in terms of latent dimensions (e.g., arousal, power and valence) and appraisals, rather than in terms of a small number of discrete emotion categories (e.g., happiness and sadness). This chapter aims to (i) give a brief overview of the existing efforts and the major accomplishments in modeling and analysis of emotional expressions in dimensional and continuous space while focusing on open issues and new challenges in the field, and (ii) introduce a representative approach for multimodal continuous analysis of affect from voice and face, and provide experimental results using the audiovisual Sensitive Artificial Listener (SAL) Database of natural interactions. The chapter concludes by posing a number of questions that highlight the significant issues in the field, and by extracting potential answers to these questions from the relevant literature. The chapter is organized as follows. Section 10.2 describes theories of emotion, Sect. 10.3 provides details on the affect dimensions employed in the literature as well as how emotions are perceived from visual, audio and physiological modalities. Section 10.4 summarizes how current technology has been developed, in terms of data acquisition and annotation, and automatic analysis of affect in continuous space by bringing forth a number of issues that need to be taken into account when applying a dimensional approach to emotion recognition, namely, determining the duration of emotions for automatic analysis, modeling the intensity of emotions, determining the baseline, dealing with high inter-subject expression variation, defining optimal strategies for fusion of multiple cues and modalities, and identifying appropriate machine learning techniques and evaluation measures. Section 10.5 presents our representative system that fuses vocal and facial expression cues for dimensional and continuous prediction of emotions in valence and arousal space by employing the bidirectional Long Short-Term Memory neural networks (BLSTM-NN), and introduces an output-associative fusion framework that incorporates correlations between the emotion dimensions to further improve continuous affect prediction. Section 10.6 concludes the chapter
Learning Landmarks Motion from Speech for Speaker-Agnostic 3D Talking Heads Generation
This paper presents a novel approach for generating 3D talking heads from raw
audio inputs. Our method grounds on the idea that speech related movements can
be comprehensively and efficiently described by the motion of a few control
points located on the movable parts of the face, i.e., landmarks. The
underlying musculoskeletal structure then allows us to learn how their motion
influences the geometrical deformations of the whole face. The proposed method
employs two distinct models to this aim: the first one learns to generate the
motion of a sparse set of landmarks from the given audio. The second model
expands such landmarks motion to a dense motion field, which is utilized to
animate a given 3D mesh in neutral state. Additionally, we introduce a novel
loss function, named Cosine Loss, which minimizes the angle between the
generated motion vectors and the ground truth ones. Using landmarks in 3D
talking head generation offers various advantages such as consistency,
reliability, and obviating the need for manual-annotation. Our approach is
designed to be identity-agnostic, enabling high-quality facial animations for
any users without additional data or training
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