Abstract: The present invention relates to a method for producing a biometric image using an optical biometric imaging arrangement including a set of micro lenses adapted to redirect incoming light onto a photodetector pixel array, the method comprising: capturing a biometric image including a set of sub-images using an optical biometric imaging device; estimating a spatial transformation between the at least one biometric sub-image and corresponding masking calibration sub-images; 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 image; and normalizing the biometric sub-images using the aligned calibration sub-images for providing a normalized biometric image based on the normalized biometric sub-images.

Abstract: Method for determining image reconstruction parameters in an optical biometric imaging device comprising a plurality of microlenses forming a microlens array and an image sensor arranged to receive light having passed through the microlenses, the method comprising: by the image sensor, capturing a plurality of sub-images together representing an image of a biometric object in contact with a sensing surface of the biometric imaging device, each sub-image corresponding to a respective microlens; and determining a demagnification factor based on at least a subset of the plurality of sub-images.

Abstract: The present invention relates to a method for producing a biometric image using an optical biometric imaging arrangement including a set of micro lenses adapted to redirect incoming light onto a photodetector pixel array, the method comprising: capturing a biometric image including a set of sub-images using an optical biometric imaging device; estimating a spatial transformation between the at least one biometric sub-image and corresponding masking calibration sub-images; 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 image; and normalizing the biometric sub-images using the aligned calibration sub-images for providing a normalized biometric image based on the normalized biometric sub-images.

Abstract: Method for determining image reconstruction parameters in an optical biometric imaging device comprising a plurality of microlenses forming a microlens array and an image sensor arranged to receive light having passed through the microlenses, the method comprising: by the image sensor, capturing a plurality of sub-images together representing an image of a biometric object in contact with a sensing surface of the biometric imaging device, each sub-image corresponding to a respective microlens; and determining a demagnification factor based on at least a subset of the plurality of sub-images.

Abstract: The invention relates to a method of a fingerprint sensing system of enabling suppressing impairment data present in an image captured by a fingerprint sensor of the fingerprint sensing system, and a fingerprint sensing system performing the method.

Abstract: The invention relates to a method of a fingerprint sensing system of extracting fingerprint feature data from an image captured by a fingerprint sensor of the fingerprint sensing system, and a fingerprint sensing system performing the method.

Abstract: The invention relates to a method of a fingerprint sensing system of enabling suppressing impairment data present in an image captured by a fingerprint sensor of the fingerprint sensing system, and a fingerprint sensing system performing the method.

Abstract: The invention relates to a method of a fingerprint sensing system of extracting fingerprint feature data from an image captured by a fingerprint sensor of the fingerprint sensing system, and a fingerprint sensing system performing the method.

Abstract: A direct conversion receiver uses an algorithm implemented by a DSP to cancel residual DC offsets during demodulation of a GMSK modulated signal. The algorithm exploits the characteristics of GMSK modulation by determining the. modulation extremes within sampled I/Q signals and calculates the DC offset as the mean of the extremes. This offset is used to weight a declining exponential function which is subtracted from the original signal samples to achieve compensation.

Abstract: A direct conversion receiver uses an algorithm implemented by a DSP to cancel residual dc offsets during demodulation of a GMSK modulated signal. The algorithm exploits the characteristics of GMSK modulation by determining the modulation extremes within sampled I/Q signals and calculates the DC offset as the mean of the extremes. This offset is used to weight a declining exponential function which is subtracted from the original signal samples to achieve compensation.