BRS BioLock, Руководство пользователя

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Centering the Core
In some cases, if the core of the fingerprint is not placed correctly, the
software may incorrectly reject a registered user. In this case, simply lift the
finger and replace it on the sensor with the core more closely centered on the
sensor. The matching process should then be performed correctly.
During enrollment, you will be asked to lift and replace your finger on the
sensor several times. The performance of the matcher can be improved by
taking care to place the finger in slightly different locations on the sensor for
each one of the enrollment placements. This gives the matcher the
opportunity to create a composite image of the finger, including more area
than can be seen in a single view.
Identification Errors
The biometric industry generally uses two principal criteria to assess the
performance of a given identification system. These are:
False Acceptance Rate (FAR) – The FAR is the measurement of the
probability that a biometric system will incorrectly identify an individual.
Statistically, the chance that two individuals will have identical
fingerprints is about one septillion to one.
False Rejection Rate (FRR) – The FRR is the measurement of the
probability that a biometric system will fail to identify an individual who is
properly enrolled.
False Acceptance
In biometric systems in general,
false acceptance
errors are the less frequent
of the two problems. In the case of the BioLock sensor, false acceptance is
extremely rare, and so far always the result of a bad enrollment.
False Rejection
For various reasons, false rejection errors are much more frequently
encountered in biometric systems. In the case of the BioLock sensor, false
rejection sometimes occurs when the core of the fingerprint is not present or
is grossly misplaced on the sensor detection surface. Lift the finger, then
replace it with more care in positioning to solve this problem.
Other causes of false rejection errors might be contamination of the sensor
surface. In addition, physiological processes such as dermatitis, disease,
aging, and calluses can obscure fingerprints. They can be mechanically
damaged – worn smooth, contaminated by dirt, etched by chemicals, or even
burned or scarred. The reduction of skin tone and elasticity due to collagen
loss in the aging process also contributes to a general deterioration of the
skin.
Most of these adverse factors do not greatly affect the performance of the
BioLock sensor because rather than interacting with the outer layer of the skin