A hybrid computer vision and Wi-Fi Doppler radar system for capturing the 3-D hand gesture trajectory with a smartphone

This paper presents a 3-D hand gesture capture technique using the 2D camera and Wi-Fi connection signals of a smartphone. The motion detection principle of this technique involves combining the algorithm of pixel-based computer vision and the extraction of Doppler shift from the reflected Wi-Fi signals. Moreover, a joint displacement calibration procedure is proposed to transform the camera pixel coordinates to the radar space coordinates. This technique has the advantages of lower computation resources and power consumption than the current counterparts and requires no extra cameras and RF transmission sources when used on a smartphone.