[John] has been working on a video-based eye tracking solution using OpenCV, and we’re loving the progress. [John]’s pupil tracking software can tell anyone exactly where you’re looking and allows for free head movement.
The basic idea behind this build is simple; when looking straight ahead a pupil is perfectly circular. When an eye looks off to one side, a pupil looks more and more like an ellipse to a screen-mounted video camera. By measuring the dimensions of this ellipse, [John]’s software can make a very good guess where the eye is looking. If you want the extremely technical breakdown, here’s an ACM paper going over the technique.
Like the EyeWriter project this build was based on, [John]’s build uses IR LEDs around the edge of a monitor to increase the contrast between the pupil and the iris.
After the break are two videos showing the eyetracker in action. Watching [John]’s project at work is a little creepy, but the good news is a proper eye tracking setup doesn’t require the user to stare at their eye.