I’ve been trying to reduce the number of free variables in the mapping between the position of the pupil in a eye-camera image and the point of gaze on a screen, given the head location of a person. Previously I was just fitting an ellipse to the pupil and using the location of its centre. This method did not use all of the information I’d just obtained about the ellipse. In this post I explore one theoretical method of using the ellipse parameters.
This post describes the relationship between the different factors I consider in my eye tracking interface set up. I go through the geometric model which I plan to use to constrain my system.
In this post I’ll be describing how I made a head mounted IR camera for tracking where a person is looking. I’ve been working on getting low-cost home brew eye tracking running on my Mac. I want the computer to know where I’m looking on the screen and to be able to interact with my gaze. My first attempt uses a head mounted IR camera to determine the pupil position and a second remote camera to detect the head position relative to the screen.
Picture 
Rachel Chapman.
(more…)
Loc-line segmented adjustable hose
In this post I describe a simple way to join sections of loc-line hose with just a bit of wire. Loc-line make an amazing product. It is a hose composed of short sections connecting with ball and socket joints. The hose can be bent into the shape you need and it will stay there. It is great for making your own gorillapod for example. Connecting the sections with your bare hands is very hard so Loc-line sell a special tool for joining the sections. But you don’t need to buy that – read on and use my easy wire method instead.
I’ve started working on a project to perform low cost eye tracking. As part of this project I need to have an infra-red (IR) camera. So I’ve converted an old Apple iSight firewire webcam in a camera sensitive to IR light. In this post I describe how to convert the iSight camera to work with IR light.
