Aarhus University Seal / Aarhus Universitets segl

Hans Gellersen

Pupil-canthi-ratio: a calibration-free method for tracking horizontal gaze direction

Research output: Contribution to book/anthology/report/proceedingArticle in proceedingsResearchpeer-review


Eye tracking is compelling for hands-free interaction with pervasive displays. However, most existing eye tracking systems require specialised hardware and explicit calibrations of equipment and individual users, which inhibit their widespread adoption. In this work, we present a light-weight and calibration-free gaze estimation method that leverages only an off-the-shelf camera to track users' gaze horizontally. We introduce pupil-canthi-ratio (PCR), a novel measure for estimating gaze directions. By using the displacement vector between the inner eye corner and the pupil centre of an eye, PCR is calculated as the ratio of the displacement vectors from both eyes. We establish a mapping between PCR to gaze direction by Gaussian process regression, which inherently infers averted horizontal gaze directions of users. We present a study to identify the characteristics of PCR. The results show that PCR achieved an average accuracy of 3.9 degrees across different people. Finally, we show examples of real-time applications of PCR that allow users to interact with a display by moving only their eyes.
Original languageEnglish
Title of host publicationAVI '14 Proceedings of the 2014 International Working Conference on Advanced Visual Interfaces
Number of pages4
Publication year2014
ISBN (print)9781450327756
Publication statusPublished - 2014
Externally publishedYes

    Research areas

  • Gaussian regression, calibration-free, eye tracking, gaze-based interaction, pervasive displays, vision-based

See relations at Aarhus University Citationformats

ID: 205586065