US 12,353,622 B2
Method and system for improving perfomance of an eye tracking system
Rickard Lundahl, Danderyd (SE); and Daniel Johansson Tornéus, Danderyd (SE)
Assigned to Tobii AB, Danderyd (SE)
Filed by TOBII AB, Danderyd (SE)
Filed on Nov. 21, 2023, as Appl. No. 18/515,353.
Claims priority of application No. 2251380-8 (SE), filed on Nov. 28, 2022.
Prior Publication US 2024/0176418 A1, May 30, 2024
Int. Cl. G06F 3/01 (2006.01); G06T 7/246 (2017.01); G06T 7/292 (2017.01); G06T 7/55 (2017.01); G06T 7/66 (2017.01); G06T 7/73 (2017.01); G06T 15/20 (2011.01)
CPC G06F 3/013 (2013.01) [G06T 7/248 (2017.01); G06T 7/292 (2017.01); G06T 7/55 (2017.01); G06T 7/66 (2017.01); G06T 7/74 (2017.01); G06T 15/20 (2013.01); G06T 2207/30201 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A method of determining an entrance pupil position of an eye of a user of an eye tracking system, the eye tracking system comprising at least a first camera arranged to provide an image of the eye, the method comprises the steps of:
determining an optical axis of the eye;
receiving an image from the first camera;
detecting an image pupil center from the received image;
determining a first estimate of the entrance pupil position in the eye using the detected image pupil center;
selecting a virtual viewpoint; and
calculating a viewpoint-adjusted entrance pupil position relating to the selected virtual viewpoint using at least the first estimate of the entrance pupil position, the optical axis of the eye and a predetermined entrance pupil displacement model, wherein the entrance pupil displacement model at least models the angular dependence of the refractive properties of a cornea of the eye and the predetermined entrance pupil displacement model in addition to modelling the angular dependence of the refractive properties of the cornea is further based on at least one of, or a combination of: variations in the cornea topography or radius; pupil size; changing accommodation; and pupil plane offset.