Han Noot

Emotion Disc and Emotion Squares: Tools to Explore the Facial Expression Space

In the paper we present two novel interactive tools, Emotion Disc and Emotion Squares, to explore the facial expression space. They map navigation in a two‐dimensional circle, by the first tool, or in two two‐dimensional squares, by the second tool, to the high‐dimensional parameter space of facial expressions, by using a small number of predefined reference expressions. They can be used as exploration tools by researchers, or as control devices by end‐users to put expressions on the face of embodied agents or avatars in applications like games, telepresence and education.

Animated CharToon faces

Human faces are attractive and effective in every-day communication. In human-computer interaction, because of the lack of sufficient knowledge and appropriate tools to model and animate realistic 3D faces, 2D cartoon faces are feasible alternatives with the extra appeal of ‘beyond realism’ features. We discuss CharToon, an interactive system to design and animate 2D cartoon faces. We give illustrations (also movies on CD) of the expressive and artistic effects which can be produced. CharToon is fully implemented in Java, allows real-time animation on PCs and through the Web. It has been used with success by different types of users.

Gesture in Style

GESTYLE is a new markup language to annotate text which has to be spoken by Embodied Conversational Agents (ECA), to prescribe the usage of hand-, head- and facial gestures accompanying the speech in order to augment the communication. The annotation ranges from low level (e.g. perform a specific gesture) to high level (e.g. take turn in a conversation) instructions. On top of that, and central to GESTYLE is the notion of style which determines the gesture repertoire and the gesturing manner of the ECA. GESTYLE contains constructs to define and dynamically modify style. The low-level tags, prescribing specific gestures to be performed are generated automatically, based on the style definition and the high-level tags. By using GESTYLE, different aspects of gesturing of an ECA can be defined and tailored to the needs of different application situations or user groups.

Variations in gesturing and speech by GESTYLE

Humans tend to attribute human qualities to computers. It is expected that people, when using their natural communicational skills, can perform cognitive tasks with computers in a more enjoyable and effective way. For these reasons, human-like embodied conversational agents (ECAs) as components of user interfaces have received a lot of attention. It has been shown that the style of the agents look and behaviour strongly influences the users attitude. In this paper we discuss our GESTYLE language making it possible to endow ECAs with style. Style is defined in terms of when and how the ECA uses certain gestures, and how it modulates its speech (e.g. to indicate emphasis or sadness). There are also GESTYLE tags to annotate text, which has to be uttered by an ECA to prescribe the usage of hand, head and facial gestures accompanying the speech in order to augment the communication. The annotation ranges from direct, low level (e.g. perform a specific gesture) to indirect, high level (e.g. take turn in a conversation) instructions, which will be interpreted with respect to the style defined. Using style dictionaries and defining different aspects like age and culture of an ECA, it is possible to tune the behaviour of an ECA to suit a given user or target group the best.

Embodied conversational agents on a common ground

One would like to rely on design guidelines for embodied conversational agents (ECAs), grounded on evaluation studies. How to define the physical and mental characteristics of an ECA, optimal for an envisioned application? What will be the added value of using an ECA? Although there have been studies addressing such issues, we are still far from getting a complete picture. This is not only due to the still relatively little experience with applications of ECAs, but also to the diversity in terms and experimental settings used. The lack of a common, established framework makes it difficult to compare ECAs, interpret evaluation results and judge their scope and relevance. In this chapter we propose a common taxonomy of the relevant design and evaluation aspects of ECAs. We refer to recent works to elicit evaluation concepts and discuss measurement issues.

Embodied Conversational Agents on a Common Ground: A Framework for Design and Evaluation

One would like to rely on design guidelines for embodied conversational agents (ECAs), grounded on evaluation studies. How to define the physical and mental characteristics of an ECA, optimal for an envisioned application? What will be the added value of using an ECA? Although there have been studies addressing such issues, we are still far from getting a complete picture. This is not only due to the still relatively little experience with applications of ECAs, but also to the diversity in terms and experimental settings used. The lack of a common, established framework makes it difficult to compare ECAs, interpret evaluation results and judge their scope and relevance. In this chapter we propose a common taxonomy of the relevant design and evaluation aspects of ECAs. We refer to recent works to elicit evaluation concepts and discuss measurement issues.

Facial Animation by Synthesis of Captured and Artificial Data

Performer-driven animation has been used with success 1, first of all to reproduce human body motion. While there are different capturing hardware-software systems to map the motion of a performer on the motion of a model of the body or face, little has been done both on the technical and on the theoretical level to support the inventive re-use of captured data.