# US 2025/0147586 A1 · Systems and methods for calibrating an eye tracking system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2025/0147586 A1 - Document ID: US20250147586A1 - Status: Published application - Kind: A1 - Application number: 19/014,836 - Filed: 2025-01-09 - Published: 2025-05-08 - Earliest claimed: 2017-10-10 - Inventors: Xiaochun Nie - Web page: https://patentgrep.com/patent/US20250147586A1 ## CPC - G06F 3/013: {Eye tracking input arrangements (G06F3/015 takes precedence)} - G06F 3/012: {Head tracking input arrangements} - G06T 7/74: {involving reference images or patches} - G06V 10/147: Details of sensors, e.g. sensor lenses (fingerprint or palmprint sensors G06V40/13; vascular sensors G06V40/145; eye sensors G06V40/19) - G06V 40/193: {Preprocessing; Feature extraction} - H04N 23/90: Arrangement of cameras or camera modules, e.g. multiple cameras in TV studios or sports stadiums - G06T 2207/30201: Face - G06V 10/62: relating to a temporal dimension, e.g. time-based feature extraction; Pattern tracking - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) - G06T: IMAGE DATA PROCESSING OR GENERATION, IN GENERAL - G06V: IMAGE OR VIDEO RECOGNITION OR UNDERSTANDING - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract Disclosed herein are various methods of calibrating relative orientation between imaging sensor and spatial orientation sensor, and relative orientation between imaging sensors. ## Claims ### Claim 1 (canceled) ### Claim 2 (canceled) ### Claim 3 (canceled) ### Claim 4 (canceled) ### Claim 5 A method comprising: obtaining an image of a pupil or limbus of a person's eye by a first imaging sensor; determining a first relative orientation of the eye with respect to the first imaging sensor based on the image; determining a second relative orientation of the eye with respect to a second imaging sensor based on the first relative orientation and based on a relationship between the first imaging sensor and the second imaging sensor. ### Claim 6 (depends on 5) The method of claim 5, further comprising: determining the relationship based on at least three pairs of relative orientations of the eye, each pair comprising a third relative orientation of the eye with respect to the first imaging sensor obtained from an image obtained by the first imaging sensor of a pupil or limbus of the eye, and each pair comprising a fourth relative orientation of the eye with respect to the second imaging sensor obtained from an image obtained by the second imaging sensor of a point the eye is gazing at. ### Claim 7 (depends on 5) The method of claim 5, wherein determining the first relative orientation is further based on a relative position of a center of the eye with respect to the first imaging sensor. ### Claim 8 (depends on 5) The method of claim 5, further comprising determining a position of a point at which the eye is gazing at, in an image obtained by the second imaging sensor, based on the second relative orientation. ### Claim 9 (canceled) ### Claim 10 (canceled) ### Claim 11 (canceled) ### Claim 12 A method comprising: while a person's head is at a first orientation and the person's eye is gazing at a point in a 3D space, obtaining a first relative orientation of the eye with respect to a first imaging sensor, and obtaining a first set of images by a second imaging sensor of a first pair of points in the 3D space; while the head is at a second orientation rotationally offset from the first orientation and the eye is gazing at the point, obtaining a second relative orientation of the eye with respect to the first imaging sensor, and obtaining a second set of images by the second imaging sensor of the first pair of points and a first set of images by the second imaging sensor of a second pair of points in the 3D space; while the head is at a third orientation rotationally offset from the second orientation about an axis along the second relative orientation of the eye and the eye is gazing at the point, obtaining a second set of images by the second imaging sensor of the second pair of points; determining a relative orientation of the first imaging sensor and the second imaging sensor based on the first relative orientation of the eye with respect to the first imaging sensor, the second relative orientation of the eye with respect to the first imaging sensor, the first set of images of the first pair of points, the second set of images of the first pair of points, the first set of images of the second pair of points, and the second set of images of the second pair of points. ### Claim 13 (depends on 12) The method of claim 12, wherein obtaining the first relative orientation of the eye with respect to the first imaging sensor or obtaining the second relative orientation of the eye with respect to the first imaging sensor is based on an image of a pupil or limbus of the eye obtained by the first imaging sensor. ### Claim 14 (depends on 12) The method of claim 12, wherein the third orientation is rotationally offset from the second orientation about an axis along a vector representing the second relative orientation of the eye. ### Claim 15 (depends on 12) The method of claim 12, wherein the first pair of points is the same as the second pair of points. ### Claim 16 (canceled) ### Claim 17 (canceled) ### Claim 18 A method comprising: while a person's head is at a first orientation and the person's eye is gazing at a first point in a 3D space, obtaining a first relative orientation of the eye with respect to a first imaging sensor, and obtaining a first set of images by a second imaging sensor of a first pair of points in the 3D space; while the head is at a second orientation rotationally offset from the first orientation and the eye is gazing at the first point, obtaining a second relative orientation of the eye with respect to the first imaging sensor, and obtaining a second set of images by the second imaging sensor of the first pair of points; while the head is at a third orientation and the eye is gazing at a second point in the 3D space, obtaining a third relative orientation of the eye with respect to the first imaging sensor, and obtaining a first set of images by the second imaging sensor of a second pair of points in the 3D space; while the head is at a fourth orientation rotationally offset from the third orientation and the eye is gazing at the second point, obtaining a fourth relative orientation of the eye with respect to the first imaging sensor, and obtaining a second set of images by the second imaging sensor of the second pair of points; determining a relative orientation of the first imaging sensor with respect to the second imaging sensor based on the first relative orientation of the eye with respect to the first imaging sensor, the second relative orientation of the eye with respect to the first imaging sensor, the third relative orientation of the eye with respect to the first imaging sensor, the fourth relative orientation of the eye with respect to the first imaging sensor, the first set of images of the first pair of points, the second set of images of the first pair of points, the first set of images of the second pair of points, and the second set of images of the second pair of points. ### Claim 19 (depends on 18) The method of claim 18, wherein obtaining the first relative orientation, the second relative orientation, the third relative orientation or the fourth relative orientation of the eye with respect to the first imaging sensor is based on an image of a pupil or limbus of the eye obtained by the first imaging sensor. ### Claim 20 (depends on 18) The method of claim 18, wherein the third orientation is rotationally offset from the second orientation. ### Claim 21 (depends on 18) The method of claim 18, wherein the third orientation and the second orientation are the same. ### Claim 22 (depends on 18) The method of claim 18, the first pair of points is the same as the second pair of points. ### Claim 23 (depends on 18) The method of claim 18, wherein the first point is the same as the second point. ### Claim 24 (canceled) ### Claim 25 (canceled) ### Claim 26 (canceled) ### Claim 27 (canceled) ### Claim 28 (canceled) ### Claim 29 (canceled) ### Claim 30 (depends on 5) A computer program product comprising a non-transitory computer readable medium having instructions recorded thereon, the instructions when executed by a computer implementing the method of claim 5. ### Claim 31 (depends on 12) A computer program product comprising a non-transitory computer readable medium having instructions recorded thereon, the instructions when executed by a computer implementing the method of claim 12. ### Claim 32 (depends on 18) A computer program product comprising a non-transitory computer readable medium having instructions recorded thereon, the instructions when executed by a computer implementing the method of claim 18.