Tobii Ab

Joakim Zachrisson

Simon Johansson

Mikael Rosell

Ylva Björk

Pravin Kumar Rana

Mark Ryan

Yimu Wang

Jonas Sjöstrand

Shanker Keshavdas

Daniel Wrang

Clément Morin

Carlos Pedreira

A controller configured to: receive first and second curve data respectively defining first and second curves respectively representative of first and second eyelid edges in an eye image; determine an eye-openness-indicator-line extending from a first intersection point on the first curve to a second intersection point on the second curve by performing an optimisation routine comprising: defining an objective function representative of: an orthogonality of the eye-openness-indicator-line to a first tangent to the first curve at the first intersection point; and an orthogonality of the eye openness indicator line to a second tangent to the second curve at the second intersection point; and adjusting a value of the first intersection point and a value of the second intersection point until at least one termination condition for a value of the objective function is satisfied; and provide an eye openness value based on a length of the eye-openness-indicator-line.

Eye openness

An eye tracking system comprises at least one illuminator and at least one image sensor configured to produce an image of an eye of a user, the image including illuminator light reflected from the eye of a user. A Fresnel lens is positioned between the image sensor and the eye of the user, through which the image sensor views the eye. Processing circuitry receives an image from the image sensor, identifies glints in the image, assigns an angular position to each glint based on an angular relationship between each glint and a centre of the Fresnel lens and determines how many glints have the same angular position. Glints are classified as false glints if more than a predetermined number of glints have the same angular position.

Method and system for glint classification

An eye tracking system comprising a controller configured to receive a reference image of an eye of a user and a current image of the eye of the user. The controller is also configured to determine a difference between the reference image and the current image to define a differential image. The differential image has a two dimensional pixel array of pixel locations that are arranged in a plurality of rows and columns. Each pixel location has a differential intensity value. The controller is further configured to calculate a plurality of row values by combining the differential intensity values in corresponding rows of the differential image and to determine eyelid data based on the plurality of row values.

Eye tracking system

Disclosed is a method for detecting a shadow in an image of an eye region of a user wearing a Head Mounted Device, HMD. The method comprises obtaining, from a camera of the HMD, an image of the eye region of the user wearing a HMD and determining an area of interest in the image, the area of interest comprising a plurality of subareas. The method further comprises determining a first brightness level for a first subarea of the plurality of subareas and determining a second brightness level for a second subarea of the plurality of subareas. The method further comprises comparing the first brightness level with the second brightness level, and, based on the comparing, selectively generating a signal indicating a shadow.

Method and device for detecting a shadow in a head mounted device

There is provided a method and system for determining if a head-mounted device for extended reality (XR) is correctly positioned on a user, and optionally performing a position correction procedure if the head-mounted device is determined to be incorrectly positioned on the user. Embodiments include: performing eye tracking by estimating, based on a first image of a first eye of the user, a position of a pupil in two dimensions; determining whether the estimated position of the pupil of the first eye is within a predetermined allowable area in the first image; and, if the determined position of the pupil of the first eye is inside the predetermined allowable area, concluding that the head-mounted device is correctly positioned on the user; or, if the determined position of the pupil of the first eye is outside the predetermined allowable area, concluding that the head-mounted device is incorrectly positioned on the user.

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Danderyd, Sweden

Joakim Zachrisson