This is computer interaction through the drawing of symbols with a pointing device cursor. Parameters for this method are either the images themselves, or certain features derived from these.
The sensing device typically uses an infrared sensor or projector for the purpose of calculating depth, Specially designed software identifies meaningful gestures from a predetermined gesture library where each gesture is matched to a computer command.
Shown below is a typical example of gesture controlled wheel chair. Styli are interfaced with display technologies to record and interpret gestures like the writing of text.
In order to capture human gestures by visual sensors, robust computer vision methods are also required, for example for hand tracking and hand posture recognition          or for capturing movements of the head, facial expressions or gaze direction.
The amount of background noise also causes tracking and recognition difficulties, especially when occlusions partial and full occur. Future of touchless technology[ edit ] There are already a vast number of companies all over the world who are producing gesture recognition technology, such as:  Intel Corp.