Graphical Processing Unit Assisted Image Processing for Accelerated Eye Tracking

Eye tracking is a well-established tool utilised in research areas such as neuroscience, psychology and marketing. There are currently many different types of eye trackers available, the most common being video-based remote eye trackers. Many of the currently available remote eye trackers are either expensive, or provide a relatively low sampling frequency. The goal of this dissertation is to present researchers with the option of an affordable high-speed eye tracker. The eye tracker implementation presented in this dissertation was developed to address the lack of low-cost high-speed eye trackers currently available. Traditionally, low-cost systems make use of commercial off-the-shelf components. However, the high frequency at which the developed system runs prohibits the use of such hardware. Instead, affordability of the eye tracker has been evaluated relative to existing commercial systems. To facilitate these high frequencies, the eye tracker developed in this dissertation utilised the Graphical Processing Unit, Microsoft DirectX and HLSL in an attempt to accelerate eye tracking tasks – specifically the processing of the eye video. The final system was evaluated through experimentation to determine its performance in terms of accuracy, precision, trackability and sampling frequency. Through an experiment involving 31 participants, it was demonstrated that the developed solution is capable of sampling at frequencies of 200 Hz and higher, while allowing for head movements within an area of 10×6×10 cm. Furthermore, the system reports a pooled variance precision of approximately 0.3° and an accuracy of around 1° of visual angle for human participants. The entire system can be built for less than 700 euros, and will run on a mid-range computer system. Through the study an alternative is presented for more accessible research in numerous application fields. ii OPSOMMING Bliknavolging is a goedgevestigde instrument wat in navorsingsareas soos neurowetenskap, psigologie en bemarking aangewend word. Daar bestaan tans heelwat verskillende tipes bliknavolgers, waarvan die algemeenste die video-gebaseerde afstandsbliknavolger is. Heelwat van die huidige beskikbare afstandsbliknavolgers is baie duur, of lewer 'n relatiewe lae proeffrekwensie. Die doel van hierdie verhandeling is om navorsers die opsie te bied van 'n bekostigbare hoëspoed bliknavolger. Die bliknavolgerstelsels wat in hierdie verhandeling aangebied word, is ontwikkel om die gebrek aan die tans beskikbare laekoste-hoëspoed-navolgers die hoof te bied. Tradisionele laekostestelsels maak gebruik van kommersiële op-die-rak-beskikbare komponente. Die hoë frekwensie waarteen die ontwikkelde stelsel funksioneer, sluit die gebruik van sulke hardeware uit. In plaas daarvan is die bekostigbaarheid van die bliknavolger beoordeel relatief tot bestaande …