Touch screens have advanced from relative obscurity in the early 1990s to become the dominant user interface technology in mobile devices today. The industry is constantly reaching for improvements in the resolution of the display, in capacitive 2-D sensing incorporating multi-touch, and the overall computing power of the device. As a result, manufacturers have been able to create a new generation of handheld devices making the internet mobile; however, the success of such products today very much relates to the user interface experience.
It is clear that 2-D gestures have changed the way how we interact with our devices. However, they are reaching their limits in terms of being intuitive and sticky. While touch continues to be an important human modality, we do live in a 3-D world. The most natural interactions for human beings are gestures which happen in three dimensions. Therefore, there is a growing desire, among consumers and device makers, to extend the way of user interaction into the space around devices. A further driver for 3-D gesture sensing is the advent of 3-D displays. When 3-D objects appear in front of a display, the only logical way to interact with the objects is through hand gestures in the same space.
There are many ways in which 3-D gestures can be used to control a device. The market will determine the right balance between intuitive control, very accurate gesture classification, and a large "dictionary" of gestures.
