Skeltrack is a Free and Open Source Software library for tracking the human skeleton joints from depth images.
It is implemented with GLib and uses plain mathematics to detect the human skeleton and although it does not use any database, it was inspired by Andreas Baak's paper: A Data-Driven Approach for Real-Time Full Body Pose Reconstruction from a Depth Camera
In this repository you will find a C++ version of Skeltrack. It is garanteed that the output of the C++ implementation is the same as the GLibC version. It is not garanteed that the code is optimized.
Although it is device agnostic, a common way of using Skeltrack is to use it together with a Kinect device, for which we recommend the freenect library.
Checking out the Test class is a good start in order to learn how to use Skeltrack.
You can find the documentation for Skeltrack here: http://people.igalia.com/jrocha/skeltrack/doc/latest/