Sign language is the primary modality of communication among deaf and mute society all over the world. Gesture use is an important part of human communication to exchange ideas, thought. The automatic recognition of gestures enriches human-computer interaction by offering a natural and intuitive method of data input. In Sign language, hand gesture is one of the typical methods of non-verbal communication for human beings and we naturally use various gestures to express our own intentions in everyday life. Till date, there have been studies on Sign language recognition based visual approach.
However, the emphasis on these works is limited to a small lexicon of sign language. This paper has summarized the researchers work in the Sign language domain and highlights the different techniques & outcomes when applied to Vision based approach used in Sign language Recognition Systems (SLRS).