Page 108 - Automated Fingerprint Identification Systems (AFIS)

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The AFIS administrator can also assign priority settings, which allow a tenprint Figure 5.3
or latent print manager to assign a higher priority than normal for processing Latent Print Workstation
a particular search, which allows the search to “jump to the head of the line”
in the transaction queue and begin processing immediately.
For latent print applications, many agencies have digital photographic equip-
ment that can capture the latent image with as much detail as possible (see Fig.
5.4). The equipment, whether purchased from the AFIS manufacturer as part
of the AFIS package or as a separate component, typically consists of a plane-
tary camera, computer equipment, and software. The software can remove or
neutralize background colors or patterns, and overlaying latent print images
can be made to appear separately. The software does not add to the latent
image; rather, it removes background “noise” to more clearly reveal the latent
print.

5.1.3 CODERS

The job of coders is to identify (i.e., extract) features from finger images such
as minutiae, direction of ridge flow, distance between minutiae, and number
of ridges between minutiae. In Figure 5.5, for example, the image on the left
shows a plain impression without any minutiae placement, while the image on
the right shows the minutiae placed by the coder following the proprietary algo-
rithm of the AFIS vendor. Coders work either on the input workstation or on