Any biometrics system operates in two phases: enrollment and verification. Biometric reference data (also referred to as template) is collected during enrollment and stored in a database or in a portable data carrier such as a smart card or token. Verification is the actual usage of the system for the desired purpose. Current biometric data is collected and compared with the reference data. The comparison process is an algorithmic approach to determine the probability that two samples stem from the same biometric trait. Depending on the outcome, access to the security system is granted or other appropriate actions taken.
The Importance of Quality Enrollment
The enrollment is crucial because the once recorded reference data will normally be used over the active lifetime of a user or his/her biometric hardware device.
A high quality enrollment process using a large sized sensor allows the system to set higher enrollment thresholds - creating buffers for real life situations like skewed finger placement, cut, worn, wet, and dry fingers.
Multiple Finger Enrollment
It is strongly recommended enrolling more than one finger. During daily life, injuries can happen that turn a registered fingerprint currently unusable. While minor cuts will not affect a robust sized sensor system (148 mm2 and larger), temporary disablilities can ocurr and shall not lock the user out of the system. It is also advisable to have a fallback mechanism in case the fingerprint logon for whatever reason currently cannot be operated. Such fallback mechanism may be a knowledge-based or another biometric modality.
A common and mass market proven method used during enrollment is taking 3 images of the same fingerprint and creating a merged enrollment dataset. This provides quality control and helps in emphasizing the most prominent characteristic features in a given print.
Supervised or Automated Process
Some applications perform enrollment as a manned service under supervision of a trained operator. In many cases, this is not feasible and the automated enrollment process has to be easy and straightforward for inexperienced users. This can be achieved by professional design of the user guidance both in hardware and software as has been proven by NEXT reference customer designs. NEXT is happy to support individual integration and implementation of stable enrollment processes.