Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A method for determining if a head-mounted device for extended reality is correctly positioned and performing a position correction procedure if the head-mounted device is determined to be incorrectly positioned, including performing eye tracking by estimating, based on a first image of a first eye of a user, a position of a pupil in two dimensions. The method also includes determining whether the estimated position of the pupil of the first eye is within a predetermined allowable area in the first image. The method also includes, responsive to determining that the estimated position of the pupil of the first eye is inside the predetermined allowable area, that the head-mounted device is correctly positioned on the user, or, responsive to determining that the position of the pupil of the first eye is outside the predetermined allowable area, that the head-mounted device is incorrectly positioned on the user.

Abstract: 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.

Abstract: 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.

Abstract: An eye tracking system provides a quality measure of a calculated gaze of a user. The eye tracking system receives gaze data including left eye gaze data associated with a left eye of the user and right eye gaze data associated with a right eye of the user. The eye tracking system compares the left eye gaze data and the right eye gaze data to determine a gaze difference value. The eye tracking system provides a gaze quality value of the gaze data based on the gaze difference value.

Abstract: 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.

Abstract: An eye tracking system receives a blink signal that represents whether or not a blink has been detected in a current image. The eye tracking system receives a quality indicator that represents a quality of data in the current image. The eye tracking system sets a validated blink signal to a validated blink value if (1) the blink signal indicates that a blink has been detected; and (2) the quality indicator is less than a validated blink threshold.

Abstract: 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.

Abstract: 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.

Abstract: 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.