Enrollment Tips

Enrollment Technique: Lock, Drop and Hold

When the amber light (LED) is on, slide the finger across the Ridge-Lock without the finger touching the sensor.

Lock: Position the finger where the first joint of the finger meets the Ridge-Lock.

Drop: Lower the finger onto the sensor and apply moderate pressure.

Hold: Keep the finger on the sensor until the top LED turns green. You may then remove the finger.

Suggested Fingers and Finger Placement

Use index, middle or ring fingers.

Avoid using thumb and pinky fingers since they are typically awkward to consistently position on the sensor.

Completely covering the area of the sensor with the fingerprint will provide the best performance.

Touching the sensor as if pressing a button creates an image that lacks information-rich fingerprint data.

Finger Position, Rotation and Pressure

Position: Placing your finger far from the center of the sensor will increase the rejection rate.

Rotation: Finger rotation should be kept to a minimum during enrollment and verification.

Pressure: Apply moderate pressure when making contact with the sensor. Too much pressure may cause smudging of the fingerprint. Too little pressure may not allow the sensor to recognize the presence of a finger. The ideal amount of pressure would be similar to a firm grip used to hold a pen.

Fingerprint Core

A fingerprint core is a area located within the inner most recurving ridge. Normally it is located in the middle of the fingerprint. The green dot represents the center of the core. An attempt should be made to ensure that the core is positioned in the center of the captured image.

The most common types of cores include:

Arches: plain and tented

Loops: singular and twinned

Whirls

Central Pocket Loops

When enrolling, place the finge on the sensor where the entire core can clearly be seen in the Fingerprint Image window. Using the Ridge-Lock as a fingerprint placement guide as described under Enrollment Technique will help to achieve this goal.

Do NOT enroll thumbs unless it is too difficult to capture an image with good quality from one of the suggested fingers.

Quality and Content

During the enrollment process, you will receive feedback regarding the Quality and Content of the captured fingerprint image. Although this information is useful in understanding certain attributes of the captured fingerprint, the actual template image should be used to determine if the enrollment will be accepted or rejected.

Good enrollments typically meet three criteria points:

  1. The fingerprint image is properly centered where the core is entirely in the field of view.
  2. The fingerprint image nearly covers all of the sensor surface.
  3. The ridges and valleys are clearly defined.

Evaluating the Fingerprint Image

The Fingerprint Image is the raw image of your captured fingerprint, before it is converted to a template. This image should be evaluated to determine if the proper moisture content has been captured.

Evaluation: Image of very moist finger; this can cause distortion of the ridge pattern.

Suggestion: Wipe the finger with a cloth or paper towel to remove excess moisture and reattempt the enrollment.  

Evaluation: Image of very dry finger; does not allow for core to be fully imaged.

Suggestion: Reattempt the enrollment to determine if more pressure allows for a larger surface area to be captured. If additional pressure does not improve the enrollment, use a small amount of lotion or moisturizer or try enrolling a different finger.

Evaluation: Good enrollment. The core is properly centered; image area is fully covered and ridge pattern is well-defined.

Suggestion: Review the Template Data image to ensure that it is also considered a good enrollment. If so, accept this enrollment.

Evaluating the Template Data Image

The Template Data image should be evaluated to determine if the enrollment should be accepted. The following are examples of such evaluations.

Evaluation: Good Enrollment. The core is properly centered; image area is fully covered and ridge pattern is well-defined.

Suggestion: Accept this enrollment.
 

Evaluation: Core is properly centered. Image is a bit fuzzy on the edges, possibly due to insufficient pressure.

Suggestion: Reattempt the enrollment to determine if more pressure eliminates the fuzzy edges. If after sufficient pressure the unclear edges remain this may be due to the fact that the user has smaller sized fingers. Accept the enrollment if multiple attempts yield similar results.

Evaluation: Core is properly centered but core is very distorted (ridges and valleys are not uniform or well defined).

Suggestion: The user may have dry fingers or may not have applied enough pressure to the sensor. Reattempt enrollment ensuring that the user applied enough pressure. If this does not eliminate the issue, please try enrolling a different finger to locate a less distorted image.

Evaluation: Core is not properly centered.

Suggestion: User should reposition finger by properly using the Ridge-Lock to try and capture more of the core. The finger should be shifted upwards to capture additional core information. If the user struggles after a couple of attempts to provide more of the core, work with the user to slide their finger along the ridge to locate the ideal position.

To download a PDF version of this page click here: Enrollment Tips.