US 11,657,642 B2
Sensor displacement compensation in an optical biometric imaging arrangement under a display
Arne Husth, Hellerup (DK)
Assigned to FINGERPRINT CARDS ANACATUM IP AB, Gothenburg (SE)
Appl. No. 17/620,176
Filed by FINGERPRINT CARDS ANACATUM IP AB, Gothenburg (SE)
PCT Filed Jun. 24, 2020, PCT No. PCT/SE2020/050658
§ 371(c)(1), (2) Date Dec. 17, 2021,
PCT Pub. No. WO2021/002791, PCT Pub. Date Jan. 7, 2021.
Claims priority of application No. 1950837-3 (SE), filed on Jul. 3, 2019.
Prior Publication US 2022/0343670 A1, Oct. 27, 2022
Int. Cl. G06V 40/13 (2022.01); G06V 10/14 (2022.01); G06V 40/12 (2022.01); G06V 10/24 (2022.01); H01L 27/146 (2006.01); G06F 3/041 (2006.01)
CPC G06V 40/1318 (2022.01) [G06V 10/14 (2022.01); G06V 10/24 (2022.01); G06V 40/1324 (2022.01); G06V 40/1335 (2022.01); G06V 40/1365 (2022.01); G06F 3/0418 (2013.01); H01L 27/14623 (2013.01); H01L 27/14627 (2013.01); H01L 27/14678 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method for producing a biometric image using an optical biometric imaging arrangement configured to be arranged under an at least partially transparent display panel and configured to capture an image of an object located on an opposite side of the at least partially transparent display panel, the optical biometric imaging arrangement including a set of microlenses adapted to redirect incoming light onto a photodetector pixel array, the method comprising:
capturing a biometric image including a set of sub-images using the optical biometric imaging arrangement;
estimating a spatial transformation between the at least one biometric sub-image and corresponding masking calibration sub-images indicative of a masking effect caused by the display panel
applying the spatial transformation to retrieved illuminance calibration sub-images adapted for illuminance calibration for captured biometric sub-images to align the illuminance calibration sub-images with the biometric sub-images; and
normalizing the biometric sub-images using the aligned illuminance calibration sub-images for providing a normalized biometric image based on the normalized biometric sub-images.