C-Libras: A Gesture Recognition App for the Brazilian Sign Language.

Sign languages are visual representations used by hearing or speech impaired people to communicate between themselves and with other people. There are over 140 sign languages globally, and they can be developed by deaf communities or derived from other existing sign languages. The signs made in this context are not considered gestures but words articulated primarily by the hands, while possibly involving facial expressions and trunk movements, making it far from trivial to understand them. Thus, automatic sign language recognition supported by machine learning has shown significant advancement in recent years. This paper presents a mobile application capable of recognizing gestures representing the letters of the Brazilian Sign Language's (Libras) alphabet. Our methodology has three steps: the construction of the gesture dataset containing all the letters of the Libras alphabet; the training of the machine learning model used in the gesture classification; and the development of the desktop/mobile application used to capture the gestures to be classified.