A framework for gaze selection techniques (Tonder et al., 2008)

Martin van Tonder, Charmain Cilliers and Jean Greyling at the Nelson Mandela Metropolitan University, South Africa presented a platform independent framework in the proceedings of the 2008 annual research conference of the South African Institute of Computer Scientists. The framework is platform independent (relying on Java) and supports multiple interaction methods such as Kumars EyePoint, popups, as well as data logging and visualization.

Abstract
Experimental gaze interaction techniques are typically prototyped from scratch using proprietary libraries provided by the manufacturers of eye tracking equipment. These libraries provide gaze data interfaces, but not any of the additional infrastructure that is common to the implementation of such techniques. This results in an unnecessary duplication of effort. In this paper, a framework for implementing gaze selection techniques is presented. It consists of two components: a gaze library to interface with the tracker and a set of classes which can be extended to implement different gaze selection techniques. The framework is tracker and operating system independent, ensuring compatibility with a wide range of systems. Support for user testing is also built into the system, enabling researchers to automate the presentation of est targets to users and record relevant test data. These features greatly simplify the process of implementing and evaluating new interaction techniques. The practicality and flexibility of the framework are demonstrated by the successful implementation of a number of gaze selection
techniques.

• van Tonder, M., Cilliers, C., and Greyling, J. 2008. A framework for gaze selection techniques. In Proceedings of the 2008 Annual Research Conference of the South African institute of Computer Scientists and information Technologists on IT Research in Developing Countries: Riding the Wave of Technology (Wilderness, South Africa, October 06 - 08, 2008). SAICSIT '08, vol. 338. ACM, New York, NY, 267-275. DOI= http://doi.acm.org/10.1145/1456659.1456690

Day One - The Eye Tracker

The choosen platform to develop the software on is Microsoft Visual Studio 2008 using .NET 3.5 and the C# (C-Sharp) programming language. Not that I´m very experienced with it (just one course) but it is similar to Sun Microsystems Java language. Besides the development environment is really nice and there´s a large amount of online resources available. Since the box is running XP all ready there is absolutely no reason to mess with it (personally I run MacPro/Os X but that´s another story)

The SMI IView RED eye tracker comes with the IView software where you can calibrate the system against points on the screen as well as other configuration aspects. After turning the tracker on and launching the calibration process I could see that the tracker is working.

Screenshot of the SMI IView program.

The calibration dots to the left usually are in full screen. To the left you can see how the eye tracker measures the reflection of the IR-lights and combines this with the location of the pupil to detect and measure eye movements. This is usually referred to as corneal reflection. The infra red light shined in my face is out of the spectrum that I can perceive. More information on eye tracking.

Clearly the the computer some how receives the data since it´s drawing circles on the screen indicating where my gaze is directed. How do I get hold of this data?

Upon an external inspection I find one firewire cable going from the tracker to the computer and two cables from the image processing box to the tracker. Seems that I must read from the firewire port. Time to Google that.

Turns out that there is an Universal Eye Tracking Driver which has been developed by Oleg Spakov at the University of Tampere, Finland. Should be a good solution so that I could easily move the application to any other supported system, including those from Swedish firm Tobii Technology. After downloading and installing the driver (which comes with source code, great!) I compiled the test application in Visual Studio to try it out. When trying to choose which tracker and what port I was using it turned out that there was no support for firewire. Seems like the previous version of IView was using USB. After some correspondence with Oleg and some tries to work around the issue it was time to stop banging my head against and RTFM like one should.

Never was much for manuals in the first place. Especially when they are 400 pages thick filled with tables of ASCII codes and references to other codes or pages. Suppose it is very much to the point, if you are a German engineer that is.. Ok. Found it. The tracker data can be sent via ethernet if IView is configured to do so. Said and done, configured IView to stream data by the UDP protocol on port 4444.

Had decided not to leave until I had the data. How do I open a datagram socket in C#? A quick search on Google should solve it. Found a pice of code that seemed to work, using a thread to open a socket to the designated port and the just read what ever data that came along. If I could print the data to the console window it.. would just be an awesome end to day one.

See next post for the C# solution..