Download:

1. Tarball from 

   http://www.inference.phy.cam.ac.uk/opengazer/

2. Or from sourceforge 

   http://sourceforge.net/projects/opengazer

   $ svn co https://opengazer.svn.sourceforge.net/svnroot/opengazer

Requirements:
  vxl >= 1.5.1           http://vxl.sourceforge.net/
  opencv >= 0.9.7    http://sourceforge.net/projects/opencvlibrary
  gtkmm-2.4 >= 2.8.0 http://www.gtkmm.org/
  cairomm-1.0 >= 0.6.0  http://cairographics.org/cairomm/
  boost >= 1.32.0    http://www.boost.org/
    
Under Debian testing:

  # apt-get install libcv-dev libhighgui-dev libcvaux-dev \
                    libgtkmm-2.4-dev libcairomm-1.0-dev libboost-dev

  (vxl must be installed from the source)           
  Important: in vxl's ccmake, set BUILD_SHARED_LIBS to ON.

Compilation:

  > tar xzf opengazer-0.1.tar.gz 
  > cd opengazer-0.1

  Edit the VXLDIR variable in the Makefile to point to your vxl
  include headers

  > make 

  Define the variable LD_LIBRARY_PATH to point to your vxl shared libraries

  > export LD_LIBRARY_PATH=$VXLDIR/lib

Instructions:

0. Make sure that you have read access to webcam device file
   (/dev/video0).  In Debian/Ubuntu you can achieve that by adding
   yourself to the video group

   > sudo addgroup $USER video

   Then logout and login again (important).

1. Set up the drivers to your camera correctly.  Put the camera into
   640x480 mode.  With pwc drivers you have to say

   > sudo rmmod pwc
   > sudo modprobe pwc size=vga

2. Put the camera centrally under you monitor, so that the height of
   your face in the image is about half of the height of the image,
   and close to the centre of the image.  Make sure the background
   light level is reasonably constant across the image.

3. Make VXLDIR point to your vxl libraries, for example 

   > export VXLDIR=/opt

   Define the variable LD_LIBRARY_PATH to point to your vxl shared libraries

   > export LD_LIBRARY_PATH=$VXLDIR/lib:$LD_LIBRARY_PATH

   Start the opengazer program

   > ./opengazer

4. While keeping your head still, use the mouse to select points on
   your face that will be used to track your head.  The first two
   points much be eye corners.  Select at least two other salient
   points (recommended 7-8 in total).  Double-clicking on an existing
   point removes it.  The first two points (corresponding to eye
   corners) will be blue, the other will be green.  When a point
   becomes red, it means that it lost track.  When you are happy with
   your selection, click "Save points".

   You need at least four points in total, but I recommend 7-8.  Once
   they have been selected, the position of your head will be tracked
   and the rotation estimates displayed as white and blue lines from
   the center of the screen.  The blue line indicates the difference
   in head position between the first frame and the current position:
   make sure that it is as short as possible at all times!

5. Now you can exit the program, run it again, click "load points",
   and the points you selected in point 3 should appear.  You have
   probably noted a white and blue line in the center of the image;
   they indicate the current rotation of your head.  The shorter the
   blue line, the closer your head position is to the original.  While
   using the gaze tracker, try to orient your head so that the length
   of the blue line is as small as possible.

6. The next step is calibration.  Remember, in order for this gaze
   tracker to work, you must keep your head absolutely still.  Press
   "Calibrate".  You will now be asked to look at various points on
   the screen, indicated by a red circle.  Remember: do not move your
   head, only your eyes!  

7. During the calibration and afterwards, a small blue will indicate
   the estimated position of your gaze focus.



DEVELOPING OPENGAZER

1. The coordinates of the calibration points are stored in
   "calpoints.txt".  Feel free to change them.  For example, by having
   only two calibration points: one on the left of the screen, and the
   other on the right, you can use opengazer as a binary switch.

2. Opengazer shows the current estimate of the gaze point as a small
   purle circle on the screen.  

   It also outputs this information to the standard output.  Each line
   has the format

   Xcoordinate Ycoordinate -> IDoftheclosestcalibrationpoint

   Opengazer also opens a local UDP socket at port 20230 to which it
   sends the current estimates X and Y.  

   To add more output methods, or to change the existing one, take a
   look at files "OutputMethods.cpp" and "OutputMethods.h".

3. Other files used by opengazer

   calpoints.txt   Coordinates calibration points 
           (as fraction of the screen)

   points.txt      Coordinates of the tracking points on the user face, in
           pixels.  This file is saved when the user clicks
           "Save points"