Ultrasonic imaging devices and methods

An authentication method, comprising:

• acquiring first image data generated by an ultrasonic sensor array, the first image data corresponding to at least one first reflected ultrasonic wave received by at least a portion of the ultrasonic sensor array from a target object during a first acquisition time window;
• acquiring second image data generated by the ultrasonic sensor array, the second image data corresponding to at least one second reflected ultrasonic wave received by at least a portion of the ultrasonic sensor array from the target object during a second acquisition time window that is shorter than the first acquisition time window;
• and
• initiating an authentication process based on the first image data and the second image data.

A non-transitory medium having software stored thereon, the software including instructions for controlling one or more devices to:

• acquire first image data generated by an ultrasonic sensor array, the first image data corresponding to at least one first reflected ultrasonic wave received by at least a portion of the ultrasonic sensor array from a target object during a first acquisition time window;
• acquire second image data generated by the ultrasonic sensor array, the second image data corresponding to at least one second reflected ultrasonic wave received by at least a portion of the ultrasonic sensor array from the target object during a second acquisition time window that is shorter than the first acquisition time window;
• and
• initiate an authentication process based on the first image data and the second image data.

An apparatus, comprising:

• means for acquiring first image data generated by an ultrasonic sensor array, the first image data corresponding to at least one first reflected ultrasonic wave received by at least a portion of the ultrasonic sensor array from a target object during a first acquisition time window;
• means for acquiring second image data generated by the ultrasonic sensor array, the second image data corresponding to at least one second reflected ultrasonic wave received by at least a portion of the ultrasonic sensor array from the target object during a second acquisition time window that is shorter than the first acquisition time window;
• and
• means for initiating an authentication process based on the first image data and the second image data.