Pupil ellipse-based, real-time iris localization
AssigneeBlink.O.G.Ltd
InventorsGilad DROZDOV, Nadav ARBEL, Tsahi MIZRAHI, Soliman NASSER, Artyom BORZIN, URI WOLLNER, Oren HAIMOVITCH-YOGEV
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Abstract
The disclosure relates to systems, methods and programs for developing real-time user-specific eye model based on iris localization using solely pupil-ellipse analysis.
Claims21
A computerized method of establishing a user-specific eye model, implementable in a system comprising a head-mounted display (HMD) configured for an off-axis capture of at least one image of at least one eye of a user, the method comprising:
- a. using the HMD, capturing a plurality of images of at least one of the user's eyes;
- b. for each image, estimating an eyeball center EC of an eyeball;
- c. projecting the eyeball to an image plane, thereby identifying a major axis R of a projected pupil ellipse;
- d. calculating a directional vector
- →
- P
- ,
- emanating from a pupil center, being normal to the major axis R, and being directed towards from the eyeball center EC;
- e. from the pupil center in each image, calculating limbus visibility angle θPL, intersected by directional vector
- →
- P
- ,
- forming limbus probable visibility angles θ1, and θ2;
- f. applying edge detection to each image, forming a plurality of edge-rendered images;
- g. in each edge-rendered image, calculating a pair of rays inscribing limbus visibility angle θPL:
- h. detecting the intersection point of each of the pair of rays with a second detected edge, thereby detecting limbus points LP1, and LP2 for each edge-rendered image;
- and
- i. using the detected limbus points from a plurality of captured images, compiling the user-specific eye-model.
A processor-readable medium implementable in a computerized system having a head-mounted display (HMD) configured for an off-axis capture of at least one image of at least one eye of a user, the processor-readable medium having a set of instructions configured, when executed, to cause the computerized system to:
- a. using the HMD, capture a plurality of images of at least one of the user's eyes;
- b. for each image, estimate an eyeball center EC of an eyeball;
- c. project the eyeball to an image plane, and identify a major axis R of a projected pupil ellipse;
- d. calculate a directional vector
- →
- P
- ,
- emanating from a projected pupil center, being normal to the major axis R, and being directed away from the eyeball center EC;
- e. from the pupil center in each image, calculate limbus visibility angle θPL, intersected by directional vector
- →
- P
- ,
- forming limbus' probable visibility angles θ1, and θ2;
- f. apply edge detection to each image, forming a plurality of edge-rendered images;
- g. in each edge-rendered image, calculate a pair of rays inscribing limbus visibility angle θPL:
- h. detect the intersection point of each of the pair of rays with a second detected edge, thereby detecting limbus points LP1, and LP2 for each edge-rendered image;
- and
- i. using the detected limbus points from the plurality of captured images, compile the user-specific eye-model.
A system comprising a head-mounted display operable to estimate the location of the center of an eyeball and an eyeball radius of a user based on iris points localized in multiple images and based on pupil ellipse measurements, wherein the location of the center of an eyeball and an eyeball radius provide a user-specific eye model that does not require recalibration when the head-mounted display (HMD) moves relative to the user's eye.
Dependencies are inferred from the claim text.