The new Samsung Galaxy S4 have and interesting new type of gestures called "Air Gesture" that use an infrared sensor to process users hand movement in front of the screen, adding a "pre-touch"/"proximity" event, in wich the fingers are detected before the touch.
I'd like to use this "Floating Touch" event in one of my apps. I searched both on Google and in the Samsung Developers Center, but I coudnt find any API or information about that.
Are the API available or is too early? Does someone have any link/info?
http://www.samsung.com/global/microsite/galaxys4/lifetask.html#page=airview
There is a good youtube video from a Google I/O session called "the sensitive side of Android" that explains how you could do something similar. Basically you use the light sensors and then you register a drop. This is quite simple but you gotta remember that changing light sources while running the app can affect the results of this feature.
That said I think they use hand detection on the front camera in order to pull off all those gestures and that would be quite complex. Also I haven't seen any api that makes it simple to do hand detection.
Yon can find it what you want
The Samsung Mobile SDK 1.5 beta1 consists of 16 independent packages; including 'Pass' and 'Motion', which allow you to make use of the Finger Print and Activity Recognition features of the Samsung GALAXY S5.
New: Accessory, Accessory File Transfer, Companion UI Profile, Health, Pass, Remote Sensor
Update: Chord, Gesture, Motion(Activity Recognition)
You can import one or more packages into your application as your project requires. For more information on the contents of each package, please check below.
If you are looking to Samsung Mobile SDK, you'll find that S4 doesn't support Gesture SDK although it had "floating gesture" function. If you google "Samsung Mobile Gesture SDK with S4", you'll find some info....
Only Galaxy J and Note 3 support Gesture SDK as far as I know.
来源：https://stackoverflow.com/questions/16649830/proximity-sensor-on-galaxy-s4-air-gestures