I would like to use a gesture, so the kinect can select the person with the gesture as the main player. After this he can control the PC. Selecting the person and giving them control is done. Now i have to implement a gesture, but i dont know how to start.
Can anyone help me?
I guess that is what you want (if you like to recognize gestures by yourself):
MS explains how to recognize a wave gesture with a full code example here:
http://blogs.msdn.com/b/mcsuksoldev/archive/2011/08/08/writing-a-gesture-service-with-the-kinect-for-windows-sdk.aspx
By now there are also some gesture recognizer toolkits available.
See this for example:
http://kinecttoolbox.codeplex.com/
You can also surf on http://channel9.msdn.com for similar projects, like that one: http://channel9.msdn.com/coding4fun/kinect/Gestures-and-Tools-for-Kinect-and-matching-Toolkit-too