Do-It-Yourself Eye Tracker: Impact of the Viewing Angle on the West Pomeranian University of Technology in Szczecin Faculty of Computer Science Do-It-Yourself Eye Tracker: Impact of the Viewing Angle on the Eye Tracking Accuracy Michał Kowalik Master's thesis supervised by: Adam Nowosielski Article supervised by: Radosław Mantiuk

Purposes Building low cost Do-It-Yourself (DIY) eye tracking system Determining accuracy of constructed eye tracking system Finding relation between the accuracy of eye tracker and an observer view angle 2018-11-08 Michał Kowalik kkowalik@wi.zut.edu.pl

How do eye trackers work? + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + Eye tracking devices determine the position of the eye and compute position of a gaze point 2018-11-08 Michał Kowalik kkowalik@wi.zut.edu.pl

Main idea of eye tracking systems The main idea of eye tracking systems is estimating the point of gaze using position of the eye in grabbed image. Image source: Riad I. Hammoud, Passive Eye Monitoring Algorithms, Applications and Experiments. Springer 2008. 2018-11-08 Michał Kowalik kkowalik@wi.zut.edu.pl

Dark and bright pupil effect Different positions of IR lamps determine two appearance types of human pupil. + Human eye in infrared light - dark pupil on the left and bright pupil on the right. 2018-11-08 Michał Kowalik kkowalik@wi.zut.edu.pl

Eye tracker accuracy The accuracy is determined by distance between target and estimated gaze point in degrees. It is measured in degrees of visual angle. Point of regard Target point + Visual angle 2018-11-08 Michał Kowalik kkowalik@wi.zut.edu.pl

Error factors affecting accuracy of eye tracker A main error affecting the accuracy of the gaze point estimation is the head movement. Others problems: extreme position of eyeball and changing illuminaton. A) Good position of eye B) extreme position of eye 2018-11-08 Michał Kowalik kkowalik@wi.zut.edu.pl

Do-it-yourself Eye Tracker Schema 2018-11-08 Michał Kowalik kkowalik@wi.zut.edu.pl

Off-the-shelf components Total cost about 30 € Elements of eye gaze tracking glasses: 1) heat shrinkable tubin, 2) negative film, 3) carbon resistor, 4) mounting strips, 5) aluminum wire, 6) IR LEDs, 7) Webcam LifeCam VX-1000, 8) safety glasses 2018-11-08 Michał Kowalik kkowalik@wi.zut.edu.pl

Eye tracking glasses (1) Webcam lens with visible light filter Preparing IR filter Creating IR LEDs circuit Capture module 2018-11-08 Michał Kowalik kkowalik@wi.zut.edu.pl

Eye tracking glasses (2) 2018-11-08 Michał Kowalik kkowalik@wi.zut.edu.pl

ITU Gaze Tracker Application An open-source gaze tracking application developed by the Gaze Group at the  IT University of Copenhagen ( http://gazegroup.org/ ) 2018-11-08 Michał Kowalik kkowalik@wi.zut.edu.pl

Perception study Participants: 10 users with an age from 21 to 56 Purpose of the test was to calculate accuracy of our eye tracking system. Participants: 10 users with an age from 21 to 56 Tracking the target points that were displayed on the screen one by one Test for 70 cm, 50 cm and 30 cm distances Calculation of accuracy Tests station 2018-11-08 Michał Kowalik kkowalik@wi.zut.edu.pl

Target points – coordinates in pixels 20 646 1273 1900 20 366 713 1060 2018-11-08 Michał Kowalik kkowalik@wi.zut.edu.pl

Horizontal (err deg / std) Results – distance 70cm Horizontal (err deg / std) 0.34 / 0.49 Vertical (err deg / std) 0.45 / 0.58 A B C D E F G H I J K L M N O P Y screen axis X screen axis 2018-11-08 Michał Kowalik kkowalik@wi.zut.edu.pl

Horizontal (err deg / std) Results – distance 50cm Horizontal (err deg / std) 0.59 / 0.75 Vertical (err deg / std) 0.55 / 0.59 A B C D E F G H I J K L M N O P Y screen axis X screen axis 2018-11-08 Michał Kowalik kkowalik@wi.zut.edu.pl

Horizontal (err deg / std) 1.77 / 1.71 Vertical (err deg / std) 1.2 / 1.03 Results – distance 30cm A B C D E F G H I J K L M N O P Y screen axis X screen axis 2018-11-08 Michał Kowalik kkowalik@wi.zut.edu.pl

Horizontal (err deg / std) 0.34 / 0.49 Vertical (err deg / std) 0.45 / 0.58 Results – distance 70cm 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 distance in degrees between target and gaze points A B C D E F G H I J K L M N O P target points 2018-11-08 Michał Kowalik kkowalik@wi.zut.edu.pl

Horizontal (err deg / std) Results – distance 50cm Horizontal (err deg / std) 0.59 / 0.75 Vertical (err deg / std) 0.55 / 0.59 0.5 1 1.5 2 2.5 distance in degrees between target and gaze points A B C D E F G H I J K L M N O P target points 2018-11-08 Michał Kowalik kkowalik@wi.zut.edu.pl

Horizontal (err deg / std) Results – distance 30cm Horizontal (err deg / std) 1.77 / 1.71 Vertical (err deg / std) 1.2 / 1.03 1 2 3 4 5 6 7 distance in degrees between target and gaze points A B C D E F G H I J K L M N O P target points 2018-11-08 Michał Kowalik kkowalik@wi.zut.edu.pl

Conclusions and future work Precision drops with wider angles of view. Accuracy of the DIY eye tracker is close to 0.6 degree for standard viewing angles Implementing validation of DIY Building low cost head tracking device and integration with the DIY eye tracker. 2018-11-08 Michał Kowalik kkowalik@wi.zut.edu.pl

SMI IVIEW X™ HED Vs DIY Eye Tracker Accuracy: 0,1° Technique: Monocular, pupil-CR, dark-pupil tracking -large cost about ~30 000€ + included head movements tracking + ready to use hardware Accuracy: 0,6° for 50cm distance Technique: monocular, dark-pupil tracking +low cost about 30€ - without head tracking - need to create hardware 2018-11-08

Thank You for Your attention! West Pomeranian University of Technology in Szczecin Faculty of Computer Science Do-It-Yourself Eye Tracker: Impact of the Viewing Angle on the Eye Tracking Accuracy Thank You for Your attention!