Gesture Recognition (part 1)

Gesture recognition can be seen as a way for computers to begin to understand human body language, thus building a richer bridge between machines and humans than primitive text user interface or even GUIs (graphical user interfaces), which still limit the majority of input to keyboard and mouse.
Gesture recognition enables humans to interface with the machine and interact naturally without any mechanical devices. Using the concept of gesture recognition, it is possible to point a finger at the computer screen so that the cursor will move accordingly. This could potentially make conventional input device such as mouse, keyboards and even touch-screens redundant.
Gesture recognition can be conducted with techniques from computer-vision and image processing.
INPUT DEVICES:

• Depth-aware cameras. Using specialized cameras such as time of flight cameras, one can generate a depth map of what is being seen through the camera at a short range, and use this data to approximate a 3d representation of what is being seen. These can be effective for detection of hand gestures due to their short range capabilities.
• stereo cameras. Using two cameras whose relations to one another are known, a 3d representation can be approximated by the output of the cameras. To get the cameras' relations, one can use a positioning reference such as a lexian-stripe or infrared emitters.
• Controller-based gestures. These controllers act as an extension of the body so that when gestures are performed, some of their motion can be conveniently captured by software. mouse gestures are one such example, where the motion of the mouse is correlated to a symbol being drawn by a person's hand, as is the wii remote, which can study changes in acceleration over time to represent gestures^.
• Single camera. A normal camera can be used for gesture recognition where the resources/environment would not be convenient for other forms of image-based recognition. Although not necessarily as effective as stereo or depth aware cameras, using a single camera allows a greater possibility of accessibility to a wider audience. 

In next part we will see the challenges and solution to these hurdles also the new invention occurred in this field.