A
P P E N D I X
A
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Q
U A L I T Y A N D
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O N T E N T
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© 1999 Biometric Identification, Inc.
Content
scores are based upon the amount of non-ambiguous data in the region
of the core. The higher the content, the greater the degree of useful information.
See Section B.3 for a thorough discussion of content
Quality
scores are based on how well the ridge pattern is defined within the
image. For best image
quality
, be sure that the sensor window is clear of dirt,
residue, or other material that can block the Veriprox’s view of the fingerprint.
See Section B.3 for a thorough discussion on quality.
Once the image is scanned, the Veriprox then creates and stores the resulting
fingerprint template.
Storing User Templates on the Veriprox
The Veriprox recognizes users by matching current images to stored templates of
previously enrolled fingerprints. Along with the fingerprint, the Veriprox requires a
proximity card with a unique user ID number
.
The Veriprox allows associating
multiple fingerprints
with a single proximity
card. Each instance of a template with a specific Id has a unique index (up to 256
indices possible (0-255)). This allows a user to have a single proximity card, but
be able to enroll multiple fingers. During
VERIFICATION,
a user waves their card
at the Veriprox reader and places their finger on the sensor. The Veriprox then will
scan the current fingerprint and compare it against all enrolled templates for that
specific card. If there are multiple templates enrolled under one card, then the
Veriprox will check templates in the numerical order based on their index.
Example:
On Card # 123, a person
ENROLLs
both their left and right index
fingers. The next time that user goes to verify, they wave Card #
123 and place a finger on the sensor. The Veriprox scans the
current finger and compares it against the first template (the right
index finger, Template ID 123 0). If a match is found, the
VERIFICATION
is PASSED and the operation ends. If a match is
not found, the Veriprox will check the second print (the left index
finger, Template ID 123 1). If a match is found, the
VERIFICATION
is PASSED and the operation ends. If the match
is not found and since all templates have been compared, the
VERIFICATION
is FAILED.
NOTE
: The initial finger scan takes ~0.5 seconds and each comparison
takes ~0.5 seconds. So if the first template results in a successful
verification, the total time is ~1.0 seconds. Successful verification
on the second templates requires ~1.5 seconds, and so on.