|
How it works
>>>>...
1
2
3
4
5
The manner in which biometric systems
extract features is a closely guarded secret, and varies from vendor
to vendor. Common physiological and behavioral characteristics used
in feature extraction include the following:
|
Technology
|
Feature Extracted
|
|
Fingerprint
|
Location and direction of
ridge endings and bifurcations on fingerprint
|
|
Voice recognition
|
Frequency, cadence and
duration of vocal pattern |
|
Facial recognition
|
Relative position and shape of
nose, position of cheekbones |
|
Iris-scan |
Furrows and striations in iris
|
|
Retina-scan
|
Blood vessel patterns on
retina |
|
Hand-scan |
Height and width of bones and
joints in hands and fingers |
|
Signature-scan
|
Speed, stroke order, pressure,
and appearance of signature |
|
Keystroke-scan
|
Keyed sequence, duration
between characters |
Template – A comparatively small
but highly distinctive file derived from the features of a user’s
biometric sample or samples, used to perform biometric matches. A
template is created after a biometric algorithm locates features in
a biometric sample. The concept of the template is one of biometric
technology’s defining elements, although not all biometric systems
use templates to perform biometric matching: some voice recognition
system utilize the original sample to perform a comparison.
Depending on when they are generated,
templates can be referred to as enrollment templates or verification
templates. Enrollment templates are created upon the user’s initial
interaction with a biometric system, and are stored for usage in
future biometric comparisons. Verification templates are generated
during subsequent verification attempts, compared to the stored
template, and generally discarded after the comparison. Multiple
samples may be used to generate an enrollment template – facial
recognition, for example, will utilize several facial images to
generate an enrollment template. Verification templates are normally
derived from a single sample – a template derived from a single
facial image can be compared to the enrollment template to determine
the degree of similarity.
Page
2 |
