A Brief Review of the Recent Trends in Sign Language Recognition

Sign language (SL) is an art of conveying our ideas and emotions non-verbally. SL is the main communication means for the deaf / dumb community. They usually communicate through a multitude of hand gestures. The correct interpretation of SL is all the more important, since the deaf and dumb constitute nearly 90 million of the world population. Therefore sign language recognition (SLR) and translation is a fertile area of research. The two main approaches for SLR are (i) image based and (ii) sensor based. Image based approach involves one or more cameras to capture an image sequence of the signer performing the sign, and then uses image processing to recognize the sign. The sensor based method uses instrumental gloves assembled with sensors to track the hand articulates. This paper mainly describes various image or vision based SLR systems comprising feature extraction and classification. Translation of SL to speech is also described briefly. Overall, this paper is expected to be a complete introduction to automatic hand gesture recognition and sign language interpretation (SLI).