# US 2025/0148828 A1 · Real-eye detection using multiple polarization configurations > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2025/0148828 A1 - Document ID: US20250148828A1 - Status: Published application - Kind: A1 - Application number: 18/838,377 - Filed: 2023-02-17 - Published: 2025-05-08 - Earliest claimed: 2022-02-24 - Assignees: Fingerprint Cards Anacatum IP AB - Applicants: Fingerprint Cards Anacatum IP AB - Inventors: Gabriel HINE; Mikkel STEGMANN - Web page: https://patentgrep.com/patent/US20250148828A1 ## CPC - G06V 40/193: {Preprocessing; Feature extraction} - G06F 21/32: using biometric data, e.g. fingerprints, iris scans or voiceprints - G06V 10/145: Illumination specially adapted for pattern recognition, e.g. using gratings - G06V 10/60: relating to illumination properties, e.g. using a reflectance or lighting model - G06V 40/161: {Detection; Localisation; Normalisation} - G06V 40/18: Eye characteristics, e.g. of the iris - G06V 40/197: {Matching; Classification} - G06V 40/40: Spoof detection, e.g. liveness detection - G06V: IMAGE OR VIDEO RECOGNITION OR UNDERSTANDING - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) ## Abstract A method of a biometric recognition system of performing real-eye detection, and a biometric recognition system performing the method. The method includes capturing a first image, comprising a representation of an iris, that is captured utilizing polarized light reflected at the iris and received at a polarization-sensitive camera, the first image being captured with a first polarization configuration being applied, and capturing a second image, comprising a representation of the iris, that is captured utilizing polarized light reflected at the iris and received at a polarization-sensitive camera, the second image being captured with a second polarization configuration being applied. The method further comprises detecting, from the representations of the iris of the first and second images, whether birefringent features of a cornea are correctly rendered in both the first and the second image, and if so determining that the iris originates from a real eye. ## Claims ### Claim 1 A method of a biometric recognition system of performing real-eye detection, comprising: capturing a first image comprising a representation of an iris, which first image is captured utilizing polarized light reflected at the iris and received at a polarization-sensitive camera capturing said first image, the first image being captured with a first polarization configuration being applied; capturing a second image comprising a representation of the iris, which second image is captured utilizing polarized light reflected at the iris and received at a polarization-sensitive camera capturing said second image, the second image being captured with a second polarization configuration being applied; detecting, from the representations of the iris of the first and second images, whether birefringent features of a cornea are correctly rendered in both the first and the second image; and if so: determining that the iris originates from a real eye. ### Claim 2 (depends on 1) The method of claim 1, wherein for each first image being captured, the first polarization configuration being applied is changed to a different polarization configuration. ### Claim 3 (depends on 1) The method of claim 1, wherein for each second image being captured, the second polarization configuration being applied is changed to a different polarization configuration. ### Claim 4 (depends on 2) The method of claim 2, wherein said different polarization configuration is selected randomly. ### Claim 5 (depends on 1) The method of claim 1, wherein a time period between the capturing of the first image and the second image is selected to vary. ### Claim 6 (depends on 5) The method of claim 5, wherein the time period between the capturing of the first image and the second image is selected to vary randomly. ### Claim 7 (depends on 1) The method of claim 1, further comprising capturing at least one further image comprising a representation of the iris, which at least one further image is captured utilizing polarized light reflected at the iris and received at the polarization-sensitive camera capturing said at least one further image, the at least one further image being captured with a further polarization configuration being applied. ### Claim 8 (depends on 1) The method of claim 1, wherein if after a set number of failed attempts have been made to detecting, from the representations of the iris of the first and second images, whether birefringent features of a cornea are correctly rendered in both the first and the second image, the user is required to prove knowledge of secret credentials before further attempts are allowed. ### Claim 9 (depends on 1) The method of claim 1, wherein the polarization if light is caused by: emitting light through a first polarization filter having a first set of polarization properties; and the polarization sensitivity being caused by: receiving the polarized light reflected by the iris at the camera via a second polarization filter having a second set of polarization properties. ### Claim 10 (depends on 9) The method of claim 9, the first and second polarization configurations being determined by the polarization properties of the first and second polarization filters. ### Claim 11 (depends on 10) The method of claim 10, wherein the first image is captured by a first image sensor of the polarization-sensitive camera, while the second image is captured by a second image sensor of the polarization-sensitive camera, the first image sensor receiving the polarized light reflected by the iris at the camera via the second polarization filter having a second set of polarization properties, and the second image sensor receiving the polarized light reflected by the iris at the camera via a third polarization filter having a third set of polarization properties. ### Claim 12 (depends on 1) The method of claim 1, further comprising: comparing the detected birefringent cornea features of at least one of the images with previously enrolled birefringent cornea features; and if there is a match: authenticating an individual associated with the detected birefringent cornea features. ### Claim 13 (depends on 12) The method of claim 12, further comprising: detecting, from the acquired representation, iris, face or periocular features; and comparing the detected iris, face or periocular features with previously enrolled iris, face or periocular features; and if there is a match an individual associated with the detected iris, face or periocular features is authenticated. ### Claim 14 (canceled) ### Claim 15 (depends on 1) A computer program product comprising a non-transitory computer readable medium, the computer readable medium having a computer program embodied thereon, the computer program comprising computer-executable instructions for causing a biometric recognition system to perform the method of claim 1 when the computer-executable instructions are executed on a processing unit included in the biometric recognition system. ### Claim 16 A biometric recognition system configured to perform real-eye detection, the system comprising a polarization-sensitive camera configured to: capture a first image comprising a representation of an iris, which first image is captured utilizing polarized light reflected at the iris and received at a polarization-sensitive camera capturing said first image, the first image being captured with a first polarization configuration being applied; capture a second image comprising a representation of the iris, which second image is captured utilizing polarized light reflected at the iris and received at a polarization-sensitive camera capturing said second image, the second image being captured with a second polarization configuration being applied; the system further comprising a processing unit configured to: detect, from the representations of the iris of the first and second images, whether birefringent features of a cornea are correctly rendered in both the first and the second image; and if so: determine that the iris originates from a real eye. ### Claim 17 (depends on 16) The biometric recognition system of claim 16, the processing unit further being configured to, for each first image being captured, change the first polarization configuration being applied to a different polarization configuration. ### Claim 18 (depends on 16) The biometric recognition system of claim 16, the processing unit further being configured to, for each second image being captured, change the second polarization configuration being applied to a different polarization configuration. ### Claim 19 (depends on 17) The biometric recognition system of claim 17, the processing unit further being configured to select said different polarization configuration randomly. ### Claim 20 (depends on 16) The biometric recognition system of claim 16, the processing unit further being configured to select a time period between the capturing of the first image and the second image to vary. ### Claim 21 (depends on 20) The biometric recognition system of claim 20, the processing unit further being configured to select the time period between the capturing of the first image and the second image is selected to vary randomly. ### Claim at position 22 -28. (canceled)