Kalman filter eye tracking

i'd like to implement a kalman filter using OpenCV to t开发者_JAVA技巧rack eye (in particular eye ball). I read something around internet about Kalman Filter. I have to set the state of my filter. What can i use as state? My only available data are 3D coordinates of eye (x,y,z).

You have to understand the Kalman filter first in order to use it. The most human readable intro with examples I have found so far is the SIGGRAPH Course Pack.

UPDATE

I do not know the Kalman filter implementation in OpenCV.

The state of the filter is perhaps the true coordinates of the eye. However, you can only estimate it from the frames (these are the coordinates you write in your question), hence the need for the filter.

To use Kalman filter as a black-box you will still need

1. an initial estimate of the state

2. measurement noise covariance R

3. process noise covariance Q

A reasonable estimate for 1. is the eye coordinates on the first frame.

As for 2. and 3., see 5.1 Parameter Estimation or Tuning in the SIGGRAPH Course pack.

Perhaps the example 4.3 An Example: Estimating a Random Constant will also help to understand how the Kalman filter works and what you need.