Japanese Sign Language Recognition Based on Three Elements of Sign Using Kinect v2 Sensor.

The visual feature of Japanese sign language is divided into two of manual signals and non-manual signals. Manual signals are represented by the shape and motion of the hands, and convey mainly the meaning of sign language words. In terms of phonology, sign language words consist of three elements: hand’s motion, position, and shape. We have developed a recognition system for Japanese sign language (JSL) with abstraction of manual signals based on these three elements. The abstraction of manual signals is performed based on Japanese sign language words dictionary. Features like coordinates of hands and depth images are extracted from manual signals using the depth sensor, Kinect v2. This system recognizes three elements independently and the final result is obtained under the comprehensive judgment from the results of three elements recognition. In this paper, we used two methods for recognition of hand shape, a contour-based method suggested by Keogh and template matching of depth image. The recognition methods of other elements were hidden Markov model for recognition of motion and the normal distribution learned by maximum likelihood estimation for recognition of position, as a same manner of our previous research. Based on our proposal method, we prepared recognition methods of each element and conducted an experiment of 400 sign language words recognition based on a sign language words dictionary.