Gesture synthesis from sign language notation using MPEG-4 humanoid animation parameters and inverse kinematics

This paper presents a novel approach for generating VRML animation sequences from sign language notation, based on MPEG-4 face and body animation. Sign language notation, in the well-known sign writing system, is provided as input and is initially converted to SWML (Sign Writing Markup Language), an XML-based format that has recently been developed for the storage, indexing and processing of sign writing notation. Each basic sign, namely signbox, is then converted to a sequence of body animation parameters (BAPs) of the MPEG-4 standard, corresponding to the represented gesture. Inverse Kinematics are also employed for synthesizing complex animation sequences (e.g. contacts). In addition, if a sign contains facial expressions, these are converted to a sequence of MPEG-4 facial animation parameters (FAPs), while exact synchronization between facial and body movements is guaranteed. These sequences, which can also be coded and/or reproduced by MPEG-4 BAP and FAP players, are then used to animate H-anim compliant VRML avatars, reproducing the exact gestures represented in the sign language notation. Envisaged applications include interactive information systems for the persons with hearing disabilities (Web, E-mail, info-kiosks) and automatic translation of written texts to sign language (e.g. for TV newscasts)