Acroprint timeQplus TQ600, User Manual

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User Identification / Verification
User identification is the process of comparing a user’s fingerprint
against a fingerprint template stored in the terminal. When a
user’s fingerprint matches a fingerprint template stored in the
TQ600 the terminal will show a successful match, thus verifying
the user’s identity.
Threshold
The threshold is a predefined number (set by the terminal system
administrator) which establishes the degree of correlation necessary
for a fingerprint comparison to be deemed a match. It can be
thought of as the minimum accuracy required to confirm a
fingerprint match. Some biometric systems call this the
“sensitivity” level. If the score resulting from a fingerprint read
compared to a fingerprint template stored in the terminal exceeds
the threshold the templates are approved as a “match” (though the
templates themselves are not identical).
The threshold establishes a balance between False Acceptance Rate
(FAR) and False Rejection Rate (FRR). FAR means the probability
that a biometric system will incorrectly identify an individual or
will fail to reject an impostor. FRR means the probability that a
biometric system will fail to identify an enrolled individual.