The rapid development of the ubiquitous computing and wearable devices witnesses a new challenge in the natural hand gesture recognition:to free the users from the constraints of the environment and the devices and help the users interact with the environment in a natural and effective way. And the mid-air gesture recognition is one of the effective methods, capable of dealing with the challenge. This paper describes the definition of the mid-air gesture at first, and then analyzes and summarizes the existing hand gesture recognition methods, based on the computer vision, the ultrasonic signal and the electromagnetic wave. At last, this paper discusses the applications of the mid-air gesture recognition, some open questions and the development in the future.

human computer interaction  /  mid-air gestures recognition  /  ubiquitous environment