This repository gathers data and code supporting the experiments in the paper Better Sign Language Translation with STMC-Transformer.


This code is based on OpenNMT v1.0.0 and requires all of its dependencies (torch==1.6.0). Additional requirements are NLTK for NMT evaluation metrics.

The recommended way to install is shown below:

# create a new virtual environment
virtualenv --python=python3 venv
source venv/bin/activate

# clone the repo
git clone
cd transformer-slt

# install python dependencies
pip install -r requirements.txt

# install OpenNMT-py
python install

Sample Usage

Data processing

onmt_preprocess -train_src data/phoenix2014T.train.gloss -train_tgt data/ -valid_src data/ -valid_tgt data/ -save_data data/dgs -lower 


python -data data/dgs -save_model model -keep_checkpoint 1 \
          -layers 2 -rnn_size 512 -word_vec_size 512 -transformer_ff 2048 -heads 8  \
          -encoder_type transformer -decoder_type transformer -position_encoding \
          -max_generator_batches 2 -dropout 0.1 \
          -early_stopping 3 -early_stopping_criteria accuracy ppl \
          -batch_size 2048 -accum_count 3 -batch_type tokens -normalization tokens \
          -optim adam -adam_beta2 0.998 -decay_method noam -warmup_steps 3000 -learning_rate 0.5 \
          -max_grad_norm 0 -param_init 0  -param_init_glorot \
          -label_smoothing 0.1 -valid_steps 100 -save_checkpoint_steps 100 \
          -world_size 1 -gpu_ranks 0


python -model model [model2 model3 ...] -src data/phoenix2014T.test.gloss -output pred.txt -gpu 0 -replace_unk -beam_size 4


# BLEU-1,2,3,4
python tools/ 1 pred.txt data/
python tools/ 2 pred.txt data/
python tools/ 3 pred.txt data/
python tools/ 4 pred.txt data/

python tools/ pred.txt data/

python tools/ pred.txt data/

To dos:

  • Add configurations & steps to recreate paper results


Please cite the paper below if you found the resources in this repository useful:

    title = "Better Sign Language Translation with {STMC}-Transformer",
    author = "Yin, Kayo  and
      Read, Jesse",
    booktitle = "Proceedings of the 28th International Conference on Computational Linguistics",
    month = dec,
    year = "2020",
    address = "Barcelona, Spain (Online)",
    publisher = "International Committee on Computational Linguistics",
    url = "",
    doi = "10.18653/v1/2020.coling-main.525",
    pages = "5975--5989",
    abstract = "Sign Language Translation (SLT) first uses a Sign Language Recognition (SLR) system to extract sign language glosses from videos. Then, a translation system generates spoken language translations from the sign language glosses. This paper focuses on the translation system and introduces the STMC-Transformer which improves on the current state-of-the-art by over 5 and 7 BLEU respectively on gloss-to-text and video-to-text translation of the PHOENIX-Weather 2014T dataset. On the ASLG-PC12 corpus, we report an increase of over 16 BLEU. We also demonstrate the problem in current methods that rely on gloss supervision. The video-to-text translation of our STMC-Transformer outperforms translation of GT glosses. This contradicts previous claims that GT gloss translation acts as an upper bound for SLT performance and reveals that glosses are an inefficient representation of sign language. For future SLT research, we therefore suggest an end-to-end training of the recognition and translation models, or using a different sign language annotation scheme.",