There is a higher chance of a wrong acceptance or reject event if a user's fingerprint is not registered properly. 

It is not recommended to lower the enroll quality lower than 80 to avoid issues in the future.


In order to improve the fingerprint authentication rate, register the fingerprint correctly. Register the fingerprint with attention to the following instructions:


Selecting a finger for fingerprint input

  • In preparation for the case that the fingerprint of a specific finger cannot be used, for example if the user is lifting a load with one hand or a finger gets hurt, up to 10 fingerprints for each user can be registered**.
  • In the case of a user whose fingerprint cannot be recognized well, the authentication rate can be improved by enrolling the same finger twice repeatedly.
  • If a finger has a cut or the fingerprint is blurry, select another finger for the fingerprint.
  • It is recommended to use the index finger or the middle finger when scanning the fingerprint. The authentication rate can be reduced if it is difficult to place another finger at the center of fingerprint sensor accurately.


** In BioStar 1, you can store 2 fingerprints for entry level devices (BioEntry Plus, BioLite Net, BioEntry W), 5 fingerprints for BioStation, and 10 fingerprints for T2

    In BioStar 2, you can store 10 fingerprints for any device.


Cautions for enrolling a fingerprint

When a fingerprint is recognized, it is compared with the initially registered fingerprint, so the initial fingerprint enroll is the most important. 

  • Place the finger deep enough to contact with the sensor completely.
  • Place the center of the fingerprint in the center of the sensor.
  • If a finger has a cut or the fingerprint is blurry, select another finger for the fingerprint.
  • Scan the fingerprint correctly without moving according to the instruction on the screen.
  • If you make the finger upright so that the contact area with the sensor has decreased or the angle of finger has warped, fingerprint authentication may not be performed.


It is very important that you include the core of the fingerprint when you register. 


Correct positioning of a finger on BioMini Plus 2 device


The below-left image is in the right position and the right image is in the wrong position. 

The scanned fingerprint from the right image position, the user won't authenticate because of the rotated fingerprint.






When fingerprint recognition fails

Suprema device can recognize a fingerprint regardless of a change of season or finger condition. However, the authentication rate may vary according to the external environment or fingerprint input method.

If the fingerprint authentication cannot be done smoothly, it is recommended to take the following measures.

  • If the finger is smeared with water or sweat, dry off the finger and then scan the finger.
  • If the finger is too dry, blow your breath on the fingertips and then scan the finger.
  • If the finger has a cut, register the fingerprint of another finger.
  • The initially registered fingerprint often may have not been scanned correctly, so register the fingerprint again according to ‘Cautions for enrolling a fingerprint’.


Please refer to the attachment for more information. 



Bad Registration Sample


Problems: 

- only a portion of the fingerprint is registered 

- core isn't registered properly because the fingerprint wasn't placed in the right position

- low number of minutiae (features of fingerprint - blue points)

 * compare with good registration example below 

- used quality score is low


Bad Registration Sample 2

Problems: 

- only a portion of the fingerprint is registered 

- core isn't registered at all because the fingerprint wasn't placed in the right position

- used quality score is low


Good Registration Sample


Notable points:

- core is properly registered

- quality score is high

- there are high number of minutiae (features of fingerprint - blue points)



Extra Tips


Advanced Enrollment

If you're enrolling user fingerprint with 2nd generation devices with the Advanced Enrollment feature, turn the feature on to receive hints on enrolling user 



If Enabled is selected, the user will be notified when the scanned fingerprint quality is low.
The enrollment process will repeat until the fingerprint is placed correctly.


Security Level

You can lower the rate of false acceptance by increasing the device security level.


This will lower the chance of false acceptance but it will also increase the rate of false reject.

Refer to the article below: 

[General] About FAR and FRR rates