After several days of debugging, our program can be compiled and run without problem at last.

Here is the introduction of our program. 

The basic principle of the program is get the skeleton information from the kinect sensor. Then, according to the position and velocity of each joint, the program decides which gesture it will triggered. 

For example, the most basic gesture-- swipe. Not only the hand joint swipes from right to left or left to right, but also its velocity should also exceed a particular limitation. By setting this limitation, the misoperations can be avoided. 

Other gestures apply the identical basic principle. 

By the way, all the gestures are realized in the 2D mode, which means all the joints are in a plane.