Lexicon for computer translation of American sign language

Abstract

This work presents a method for translation of American Sign Language (ASL) to English using a feature-based lexicon, designed to exploit ASL's phonology by searching the lexicon for the sign's manual and non-manual information. Manual sign information consists of phonemes sig (movement), tab (location), dez (handshape), and ori (hand orientation), which we use as the ASL unit of analysis. Non-manual sign information consists of specific facial and body configurations. A camera acquires the sign and individual frames are analyzed and values assigned to the sig, tab, dez, and ori sign parameters as well as other sign features, for referencing during lexicai search. ASL formational constraints are exploited to target specific image segments for analysis and linguistic constraints serve to further reduce the lexical search space. Primary keys for lexical search are sig and tab, the most discriminating sign features, followed by the remaining features, as necessary, until a single lexical entry is extracted from the lexicon. If a single lexical candidate cannot be determined, an exception is raised, signaling search failure. This method of using ASL phonological constraints to aid image analysis and lexical search process simplifies the task of sign identification. © Springer-Verlag Berlin Heidelberg 1998.