Web GIS in practice X: a Microsoft Kinect natural user interface for Google Earth navigation

Launched in November 2010, Kinect is a motion sensing USB (Universal Serial Bus) input device by Microsoft that enables users to control and naturally interact with games and other programs without the need to physically touch a game controller or object of any kind. Kinect achieves this through a natural user interface by tracking the user's body movement and by using gestures and spoken commands [1,2]. Kinect holds the Guinness World Record as the fastest selling consumer electronics device, with sales surpassing 10 million units as of 9 March 2011 [3].Kinect uses technology by Israeli company PrimeSense that generates real-time depth, colour and audio data of the living room scene. Kinect works in all room lighting conditions, whether in complete darkness or in a fully lit room, and does not require the user to wear or hold anything [4,5] (cf. Sony's PlayStation Move and Nitendo Wii Remote controllers). PrimeSense also teamed up with ASUS to develop a PC-compatible device similar to Kinect, which they called ASUS Xtion and launched in the second quarter of 2011 [2,6].Kinect is a horizontal bar connected to a small base with a motorised pivot (to follow the user around, as needed), and is designed to be positioned lengthwise above or below the computer or TV screen (Figure 1). The device features an RGB (Red Green Blue) colour camera, a depth sensor (using an infrared--IR projector and an IR camera), and a noise-cancelling, multi-array microphone (made of four microphones, which can also contribute to detecting a person's location in 3-D (three-dimensional) space) [5,7]. Kinect also incorporates an accelerometer (probably used for inclination and tilt sensing, and possibly image stabilisation [7]). Running proprietary firmware (internal device software), these components together can provide full-body 3-D motion capture, gesture recognition, facial recognition, and voice recognition capabilities [2,4]. (Functions, accuracy and usability will also greatly depend on