US 9,851,791 B2Granted

Dynamic eye tracking calibration

AssigneeFacebook, Inc.

InventorsJavier San Agustin Lopez, Martin Henrik Tall, Benjamin Antoine Georges Lefaudeux, Henrik Hegner Tomra Skovsgaard

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Abstract

A user of a computing device may interact with and control objects and applications displayed on the computing device through the user's eye movement. Detected gaze locations are correlated with actions performed by the user and compared with typical gaze locations for those actions. Based on differences between the detected and expected gaze locations, the eye tracking system can be recalibrated. An area around a gaze location encompassing a set of likely active locations can be enlarged, effectively prompting the user to interact with the desired active location again. The enlarging of the area serves to separate the active locations on the screen, reducing the probability of interpreting the user's gaze incorrectly.

Claims20

Dependent claims

A device comprising:

a display;
a memory having instructions embodied thereon;
and
one or more processors configured by the instructions to perform operations comprising:
maintaining a buffer with gaze information of a user of a computing device, the gaze information including one or more elements of data for each gaze capture, the one or more elements of data identifying an estimated gaze location that provides an estimation of a position on the display where the user is looking at a timestamp, the one or more elements of data being determined for each gaze capture by an eye tracking module at the timestamp based on light captured by a camera of the eye tracking module after reflection from an eye of the user;
during execution of an application on the computing device, detecting a user interaction at an interaction location on the display of the computing device, the user interaction occurring at an interaction time;
in response to the detection of the user interaction, selecting a portion of the gaze information from the buffer, the selected portion comprising information about one or more gaze captures occurring within a threshold time period before the interaction time;
based on the portion of the gaze information and the interaction location, calculating one or more calibration parameters specific to the user including at least one of:
offsets between optical and visual axes of the eye, a radius of a cornea of the eye, a distance between a center of the cornea and a center of a pupil of the eye;
determining, by the eye tracking module, eye feature information including components of a vector difference between the center of the pupil and a corneal reflection of the eye;
and
computing a point of regard of the user on the display based on the eye feature information and the one or more calibration parameters.

9 more elements

A method comprising:

maintaining a buffer with gaze information of a user of a computing device, the gaze information including one or more elements of data for each gaze capture, the one or more elements of data identifying an estimated gaze location that provides an estimation of a position on a display of the computing device where the user is looking at a timestamp, the one or more elements of data being determined for each gaze capture by an eye tracking module at the timestamp based on light captured by a camera of the eye tracking module after reflection from an eye of the user;
during execution of an application on the computing device, detecting a user interaction at an interaction location on the display of the computing device, the user interaction occurring at an interaction time;
in response to the detection of the user interaction, selecting a portion of the gaze information from the buffer, the selected portion comprising information about one or more gaze captures occurring within a threshold time period before the interaction time;
based on the portion of the gaze information and the interaction location, calculating one or more calibration parameters specific to the user including at least one of:
offsets between optical and visual axes of the eye, a radius of a cornea of the eye, a distance between a center of the cornea and a center of a pupil of the eye;
determining, by the eye tracking module, eye feature information including components of a vector difference between the center of the pupil and a corneal reflection of the eye;
and
computing a point of regard of the user on the display based on the eye feature information and the one or more calibration parameters.

5 more elements

A non-transitory machine-readable storage medium storing instructions which, when executed by one or more processors, cause the one or more processors to perform operations comprising:

maintaining a buffer with gaze information of a user of a computing device, the gaze information including one or more elements of data for each gaze capture, the one or more elements of data identifying an estimated gaze location that provides an estimation of a position on a display of the computing device where the user is looking at a timestamp, the one or more elements of data being determined for each gaze capture by an eye tracking module at the timestamp based on light captured by a camera of the eye tracking module after reflection from an eye of the user;
during execution of an application on the computing device, detecting a user interaction at an interaction location on the display of the computing device, the user interaction occurring at an interaction time;
in response to the detection of the user interaction, selecting a portion of the gaze information from the buffer, the selected portion comprising information about one or more gaze captures occurring within a threshold time period before the interaction time;
based on the portion of the gaze information and the interaction location, calculating one or more calibration parameters specific to the user including at least one of:
offsets between optical and visual axes of the eye, a radius of a cornea of the eye, a distance between a center of the cornea and a center of a pupil of the eye;
determining, by the eye tracking module, eye feature information including components of a vector difference between the center of the pupil and a corneal reflection of the eye;
and
computing a point of regard of the user on the display based on the eye feature information and the one or more calibration parameters.

5 more elements

Dependencies are inferred from the claim text.

Facts

Application: 14/940,658Filed 13 Nov 2015 · us provisional application
Priority: 14 Nov 2014
Published: US 2016/0139665 A119 May 2016
Granted: 26 Dec 2017
Term ends: Not estimatedThe source records don’t support an estimate.

Classification8 codes

G06F 3/013
Arrangements for interaction with the human body, e.g. for user immersion in virtual reality: eye tracking input arrangements
G06F 3/038
Pointing devices displaced or positioned by the user , e.g. mice, trackballs, pens or joysticks; Accessories therefor: control and interface…
G06F 3/04842
For the control of specific functions or operations, e.g. selecting or manipulating an object, an image or a displayed text element, setting a…:…
G06T 7/70
Image analysis: determining position or orientation of objects or cameras