// Authors: Gabriele Fanelli, Thibaut Weise, Juergen Gall, BIWI, ETH Zurich
// Email: fanelli@vision.ee.ethz.ch

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// When using this software, please acknowledge the effort that
// went into development by referencing the paper:
//
// Fanelli G., Weise T., Gall J., Van Gool L., Real Time Head Pose Estimation from Consumer Depth Cameras
// 33rd Annual Symposium of the German Association for Pattern Recognition (DAGM'11), 2011

13.10.2011: removed bug in CRForestEStimator::estimate (thanks to Cristobal Belles)


The actual code for head pose estimation is contained in the CR* files present in this folder. The main.cpp file shows an example use of the code on (compressed) depth images
as the ones provided in the data/ folder.
A forest is provided in the trees/ folder, which was trained on depth images of people turning theirs heads in front of the Kinect, sitting at around 1 m distance from the sensor;
therefore, the forest will give optimal results for similar scenarios. 

In order to compile, OpenCV2.3 is required, please modify the CMakeLists.txt file according to your local OpenCV installation.

To run the example code, type ./head_pose_estimation config.txt data/frame_XXXX_depth.bin
The config.txt file contains all parameters needed for the head pose estimation, e.g., the path to the forest, the stride, and z threshold used to segment the person from the background.
Please note that a depth.cal file should be present in the same folder as the depth image.

In the "code/" folder, an additional example is provided which runs on a stream of depth images coming from a Kinect sensor. The demo requires
(in addition to OpenCV), the OpenNI, freeglut, and OpenGL libraries.
For installing OpenNI on Ubuntu 11.4, I recommend using this tutorial 
http://tirokartblog.wordpress.com/2011/06/22/kinect-driver-and-samples-installation-on-ubuntu-11-04/

To run the demo, type ./head_pose_estimation_demo config.txt