User's Manual

A -Optimizing Fingerprint Images  61
Proprietary
A Optimizing Fingerprint Images
A.1 Positioning the Finger on the Fingerprint Sensor
During enrollment, be sure to properly position the finger on the sensor. Figure A-1 illustrates
poorly placed fingers. The Cogent algorithm will reject images that do not contain enough
minutiae points.
Figure A-1 Improper Finger Placement
Finger Issue
Finger 1 The finger is positioned too high on the sensor and does not offer enough
information to accurately enroll an image.
Finger 2
The finger is positioned too low on the sensor and may not be properly
enrolled.
Finger 3
And
Finger 4
The fingers are off-center and somewhat rotated. Both of these fingerprint
images can result in a failure to properly identify them later on, even if enough
minutiae points have been detected.
To ensure successful fingerprint capture, the finger should be properly centered with the
application of even pressure and minimal rotation. Figure A-2 is an example of proper finger
placement.