A processor-implemented method with image preprocessing includes: transforming a fingerprint image into a frequency domain; suppressing a low-frequency region corresponding to a first noise component of the fingerprint image in the frequency domain; and restoring the frequency domain, in which the low-frequency region is suppressed, as an image.

A system described herein may provide a technique for the use of machine learning techniques to perform authentication, such as biometrics-based user authentication. For example, user biometric information (e.g., facial features, fingerprints, voice, etc.) of a user may be used to train a machine learning model, in addition to a noise vector. A representation of the biometric information (e.g., an image file including a picture of the user's face, an encoded file with vectors or other representation of the user's fingerprint, a sound file including the user's voice, etc.) may be iteratively transformed until the transformed biometric information matches the noise vector, and the machine learning model may be trained based on the set of transformations that ultimately yield the noise vector, when given the biometric information.

A method may involve receiving fingerprint sensor data from a fingerprint sensor system, detecting, according to the fingerprint sensor data, a presence of a digit on an outer surface of the apparatus in a fingerprint sensor system area; determining, according to the fingerprint sensor data, a digit force or a digit pressure of the digit on the outer surface of the apparatus; and making, according to the fingerprint sensor data, a time threshold determination. The time threshold determination may involve determining whether a length of time during which the digit force exceeds a threshold digit force or during which the digit pressure exceeds a threshold digit pressure is greater than or equal to a threshold length of time. The method may involve determining, based at least in part on the time threshold determination, whether to enable one or more emergency response functions of the apparatus.

A gesture recognition system and a gesture recognition method are provided. The gesture recognition system includes a fingerprint sensor and a processing circuit. The processing circuit obtains a first fingerprint image and a second fingerprint image through the fingerprint sensor. The processing circuit obtains a plurality of first coordinate parameters of a plurality of first coordinate points in the first fingerprint image, and obtains a plurality of second coordinate parameters of a plurality of second coordinate points in the second fingerprint image. The first coordinate points of the first fingerprint image and the second coordinate points of the second fingerprint image respectively have a plurality of grayscale values corresponding to each other. The processing circuit determines a gesture operation according to the first coordinate parameters and the second coordinate parameters.

A first period when detection of a detection target body in contact with or proximity to a sensor is performed and a second period when detection of asperities on a surface of the detection target body is performed are set. First regions are set in a detection region of the sensor as input keys for a password. In the first period, one of segmented regions obtained by dividing a second region the center of which corresponds to coordinates of a touch detection position when the touch detection position for inputting of the password is detected in one of the first regions. In the second period, based on priorities set in advance according to the number of feature points of the detection target body, a segmented image detected in the segmented region for the inputting is output, and a certain number of segmented images are synthesized to generate a fingerprint image.

A method for controlling a plurality of ultrasonic transducers in a fingerprint sensing system that comprises a cover plate having a sensing surface configured to be touched by a finger, and a plurality of ultrasonic transducers located at the periphery of the cover plate and configured to transmit an acoustic signal propagating in the cover plate, receive an ultrasonic signal having interacted with an object in contact with the sensing surface, and to determine properties of the object based on the received ultrasonic signal. The method comprises: in response to a first input, controlling the plurality of transducers such that at least a portion of the sensing surface has a first feature detection resolution; and in response to a second input, controlling the plurality of transducers such that at least a portion of the sensing surface has a second feature detection resolution, different from the first feature detection resolution.

A touch-based method for user authentication includes a training stage and an authentication stage. The training stage includes: generating, by a touch interface, a plurality of training touch parameters; and generating, by a processor, a training heat map according to the plurality of training touch parameters. The authentication stage includes: generating, by the touch interface, a plurality of testing touch parameters; generating, by the processor, a testing heat map according to the plurality of testing touch parameters; comparing, by the processor, the testing heat map with the training heat map to generate an error map; and generating, by the processor, one of pass signal and fail signal according to the error map.

A method for identifying a user using an image of an object of the user, the method comprising: obtaining, by an optical sensor of a mobile device, the image of the object, wherein the object comprises a biometric characteristic of the user; providing the image to a neural network; processing the image by the neural network to identify-a position of the object and the object in the image; extracting, from the identified object, the biometric characteristic; storing the biometric characteristic in a storage devices and providing at least the biometric characteristic as input to an identification means to determine whether the biometric characteristic identifies the user.

A sensing circuit has a plurality of sensing units and a plurality of sensing electrodes. The sensing electrodes are divided into a first group and a second group. The sensing electrodes of the first group are electrically connected to a portion of the sensing units, and the sensing electrodes of the second group are electrically connected to another portion of the sensing units. A first sensing signal is provided to the sensing electrodes of the first group in a first time period, and a second sensing signal is provided to the sensing electrodes of the second group in a second time period. The first time period and the second time period start at different times and are not overlapped with each other.

A display control apparatus includes: a setting unit that sets a parameter according to an input of a user; a determination unit that determines, for each of areas of a fingerprint image obtained by dividing the fingerprint image, whether quality of a ridge pattern in the area is satisfactory or not based on the parameter; and a first display control unit that makes display means display the fingerprint image according to a result of the determination.