The Importance of a Good Enrollment

event_note November 09, 2016

How does BioID recognize my face?

We naturally recognize each other by the way our faces look. BioID works in much the same way. To be recognized, you look into a webcam or smart phone camera and one or more photos are captured. BioID first finds your face in the picture using our patented face finder. The image is then cropped and converted to black and white.

Then the unique characteristics of your face, such as the relative sizes of and distances between facial features, are extracted into a mathematical representation. This is compared with the biometric template generated when you enrolled. The analysis does not look at eye color, skin color, hair color or style, etc.

Why is the quality of the enrollment so important?

Enrollment allows you to “present” to BioID how you look and sound. It is extremely important because this is the only chance to “register” your biometrics so only you can be recognized as who you are.

Since you don’t always look the same every time you need to be recognized (due to lighting, expression, physical condition), the key to a good enrollment is a variety of photos that represent the ways you might look when you need to be recognized. If your face enrollment consists only of pictures of you in perfect lighting, you may not be recognized when the lighting is not so good.

Likewise, the way you sound can vary from day to day depending on your mood, energy level or illness. If your voice enrollment sounds like a robot, you may not be recognized when you use a more natural voice.

The better your enrollment represents the range of your natural “looks” or “sounds”, the more quickly and easily you will be recognized in the future. 

How can I make a good enrollment facial image?

Enrolling your face is as simple as taking a few selfies. For best results:

  • Look straight at the camera, keeping it at eye level. To protect your privacy and ensure high recognition rates, BioID is purposely designed to work with full-front or nearly full-front facial images, but with very slight differences in head position (center, up, down, left, right). Your application may guide you to enroll in a specific way.
  • Show your whole face and eyes. Don’t hide your eyes with too much hair, clothing, or dark glasses.
  • Be natural, the way you normally look.
  • Allow for variety. You don’t always look the same, especially due to lighting, so enroll under different lighting conditions in which you might need to be recognized (natural light, artificial light, dark, light from front / behind / side). On a mobile device one simple trick is to enroll yourself facing one direction, then turn your body and phone 90 degrees so the background is different and enroll again, and so on in all directions. In most environments this will naturally result in lighting variety.

Will changes such as a new hairstyle, glasses, facial hair, or make-up affect recognition?

Changes in hairstyle, unless the hair covers the face area, will not make a difference. Make-up typically does not affect recognition unless it is very heavy (stage) make-up.

You may add more enrollment images if something in your face changes significantly (after an accident or cosmetic surgery, or if you radically change eyeglasses, facial hair, facial jewelry, etc.) 

Will my face / voice still be recognized after months or years?

The features BioID concentrates on are relatively stable, so most people can be recognized even after much time has passed. Furthermore, BWS supports optional auto-learning, in which successful verification images are added to the user’s enrollment. In this way the template adapts and changes with the user.

When do I need to enroll again?

When you first use BioID you may wish to enroll a few times at different times of days or in different locations under a variety of environmental conditions. Once you can be reliably recognized, you only need to enroll again if:

  • Something in your face changes significantly (such as after an accident or cosmetic surgery, or if you radically change eyeglasses, facial hair, facial jewelry, etc.)
  • You have a cold and your voice sounds a bit different than it normally would
  • You often have to try more than once to be recognized. Once recognized, BioID typically adjusts itself to adapt to the changes right away.