A Formal Language to Describe and Animate Signs in Brazilian Sign Language

Danilo Assis Nobre dos S. Silva, Tiago Maritan Ugulino de Araújo, Leonardo Dantas, Vandhuy F. Martins, Yúrika Sato Nóbrega, Hozana Raquel Gomes de Lima, Guido Lemos de Souza Filho


In this paper, we propose the definition of a formal, expressive and consistent language to describe signs in Brazilian Sign Language (LIBRAS). This language allows the definition of all parameters (phonemes) of a sign and from this definition an animation is generated based on a 3D humanoid avatar. The proposed language is also flexible in the sense that it has mechanisms to include new parameters (or phonemes) “on the fly”. In order to provide a case study for the proposed language, a human computation system for collaborative construction of a LIBRAS vocabulary was also developed. This system, called WikiLIBRAS, allows deaf users and LIBRAS interpreters to describe signs and generate animations for signs in LIBRAS. Some preliminary tests with Brazilian deaf users and LIBRAS interpreters were also performed to evaluate the proposal. Our preliminary evaluation indicates that the proposed language can represent a significant number of signs in LIBRAS and WikiLIBRAS users can generate signs in LIBRAS more productively than 3D designers.


deaf; sign language; LIBRAS, generation; formal language; humanoid avatars

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