Method and system for accommodating pupil non-concentricity in eyetracker systems
AssigneeLC Technologies, Inc.
InventorDixon Cleveland
Life of this patent
Estimating the term…
Abstract
Embodiments of the present invention relate to eyetracking methods and systems that compensate for physiological variations in the location of the pupil within the eye. In one embodiment, a video eyetracker measures the location of a pupil within the eye. Using measured observable features of the eye, including pupil diameter, a pupil-location-offset is estimated with respect to a fixed point on the eyeball. The location of a fixed point within the eyeball is estimated as a function of the measured pupil location and the estimated pupil-location-offset.
Claims44
A method to determine the location of a fixed point within an eyeball comprising the following steps:
- measuring the location of a pupil;
- measuring at least one observable feature of the eye related to the relative location of the pupil within the eyeball;
- estimating a pupil-location-offset with respect to the fixed point on the eyeball using the at least one measured observable eye feature;
- and
- calculating the location of the fixed point within the eyeball as a function of the measured pupil location and the estimated pupil-location offset.
A method of using a computer system to quantify an eye's pupil-offset behavior, comprising the following steps:
- using an eyetracker system and the pupil-center-corneal reflection method to measure a first glint-pupil vector of the eye;
- fixating the eye on one or more given points on a screen;
- measuring at least one additional glint-pupil vector of the eye;
- and
- quantifying measured pupil offsets as functions of measured pupil diameters.
An apparatus for determining the location of a fixed point within an eyeball comprising:
- a computer;
- a camera coupled to the computer for observing the eye;
- a means for measuring pupil location;
- means for measuring at least one observable feature of the eye related to the relative location of the pupil within the eyeball;
- a processor for estimating a pupil-location-offset with respect to a fixed point on the eyeball using the at least one measured observable eye feature;
- and
- a processor for estimating the location of the fixed point within the eyeball as a function of the measured pupil location and the estimate of the pupil-location offset.
A video eyetracking system comprising:
- means for measuring a pupil center location of an eyeball within a video image;
- means for estimating an offset of the pupil center location with respect to a fixed reference point on the eyeball;
- means for determining an offset-adjusted pupil-center using the offset estimate and the measured pupil center location;
- and
- a processor that uses the offset-adjusted pupil-center to measure the orientation of the eyeball.
Dependencies are inferred from the claim text.