Multi-stage liveness determination

摘要

A method of determining whether a biometric object is part of a live individual is described. In one such method, image information is acquired from the biometric object by using a sensor, such as an ultrasonic sensor. The image information may be analyzed in at least two analysis stages. One of the analysis stages may be a temporal analysis stage that analyzes changes in the image information obtained during a time period throughout which the biometric object was continuously available to the sensor. For example, a dead/alive stage may analyze differences between image information taken at two different times in order to identify changes from one time to the next. Other stages may focus on aspects of a particular image information set, rather than seeking to assess changes over time. These other stages seek to determine whether an image information set exhibits characteristics similar to those of a live biometric object.

主权项

1. A method of determining whether a biometric object is part of a live individual, comprising:
acquiring image information from the biometric object using an ultrasonic sensor, wherein acquiring the image information involves a plurality of range gate delays and a plurality of ultrasonic frequencies; and analyzing the image information in at least two analysis stages, wherein one of the analysis stages is a temporal analysis stage that analyzes changes in the image information obtained during a time period throughout which the biometric object was continuously available to the sensor and the other of the analysis stages involves analyzing the image information to determine whether the biometric object includes at least one manufactured layer.