Gloss2Text: Sign Language Gloss translation using LLMs and Semantically Aware Label Smoothing
Pooya Fayyazsanavi, Antonios Anastasopoulos, Jana Košecká
TL;DR
The paper addresses sign language Gloss2Text translation by converting gloss sequences into spoken German using fine-tuned large language models. It combines data augmentation (paraphrasing via an intermediate language and back-translation) with a Semantically Aware Label Smoothing loss that leverages word embedding similarities to soften incorrect predictions near the target meaning. On the PHOENIX-2014T dataset, the approach achieves state-of-the-art results with notable gains in BLEU, ROUGE, and CHRF++ while using parameter-efficient adapters, and ablations confirm the contributions of SALS and data augmentation. The work demonstrates the potential of LLM-based gloss-to-text translation for sign languages and highlights directions for improving robustness and cross-domain generalization.
Abstract
Sign language translation from video to spoken text presents unique challenges owing to the distinct grammar, expression nuances, and high variation of visual appearance across different speakers and contexts. The intermediate gloss annotations of videos aim to guide the translation process. In our work, we focus on {\em Gloss2Text} translation stage and propose several advances by leveraging pre-trained large language models (LLMs), data augmentation, and novel label-smoothing loss function exploiting gloss translation ambiguities improving significantly the performance of state-of-the-art approaches. Through extensive experiments and ablation studies on the PHOENIX Weather 2014T dataset, our approach surpasses state-of-the-art performance in {\em Gloss2Text} translation, indicating its efficacy in addressing sign language translation and suggesting promising avenues for future research and development.
