The Eye of the Beholder Automatic recognition of Dutch sign language

Preface For as long as I can remember, I have been interested in languages. Sign languages especially fascinate me, because they are natural languages using a different modality: sign languages use images as the vehicle for information. This has strange implications: in sign language, it is easy to have a conversation with someone at the other side of a crowded room. On the other hand, it is impossible to talk to someone whose back is turned. It is such characteristics, such differences from spoken languages, that make sign languages so interesting to me. I have studied Artificial Intelligence at the University of Groningen. I chose the direction 'Language-and Speech Technology'. For my final thesis, I wanted to set up my own research project at the university. My interest in sign languages motivated me to investigate the sign language side of a certain research area of Artificial Intelligence: the automatic processing of natural language. This area is also known as 'speech recognition', because it has mainly been investigating spoken languages. Investigating sign recognition is therefore interesting, because it could give us more insight into natural language processing: are techniques designed for speech recognition applicable to sign recognition, too? Or does the fact that they are designed for the characteristics of spoken languages mean that they are unsuitable for a language in a visual modality? The reverse is also interesting: can techniques developed for sign recognition be utilised by automatic speech recognition? I chose to work with Dutch sign language. To my knowledge, this is the first time automatic recognition has been investigated for Dutch sign language. Apart from the scientific value, research into sign language recognition also serves a social purpose. Sign language users are minority groups practically everywhere, because usually less than 0.1% of a population is deaf. The majority of a population will therefore not speak sign language, which causes sign language communities to be somewhat isolated. So if techniques could be developed for the processing of natural sign languages, an application for interpreting sign language could be built, which would make communication between deaf and hearing easier.