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How Facial Recognition Systems Work

Rubina Khan, Varsha Tarate, Roopali Donwalkar and Manish Parekh
Sir J.J. Girls' High School
Sir J.J. Fort Boys' High School

People have an amazing ability to recognize and remember thousands of faces. But computer can do better than people. Computers can turn your face into computer code so it can be compared to thousands, if not millions, of other faces. Facial recognition software is being used in elections, criminal investigations and to secure your personal computer.

The Face
Your face is an important part of who you are and how people identify you. Imagine how hard it would be to recognize an individual if all faces looked the same. Except in the case of identical twins, the face is arguably a person's most unique physical characteristic. While humans have had the innate ability to recognize and distinguish different faces for millions of years, computers are just now catching up.
Visionics, a company based in New Jersey, is one of many developers of facial recognition technology. The twist to its particular software, FaceIt, is that it can pick someone's face out of a crowd, extract that face from the rest of the scene and compare it to a database full of stored images. Facial recognition software is based on the ability to first recognize faces, which is a technological feat in itself, and then measure the various features of each face.

Facial recognition software is designed to pinpoint a face and measure its features.
If you look in the mirror, you can see that your face has certain distinguishable landmarks. These are the peaks and valleys that make up the different facial features. Visionics defines these landmarks as nodal points. There are about 80 nodal points on a human face. Here are a few of the nodal points that are measured by the software:
• Distance between eyes
• Width of nose
• Depth of eye sockets
• Cheekbones
• Jaw line
• Chin

These nodal points are measured to create a numerical code, a string of numbers, that represents the face in a database. This code is called a face print. Only 14 to 22 nodal points are needed for the FaceIt software to complete the recognition process.

The Software
Facial recognition software falls into a larger group of technologies known as biometrics. Biometrics uses biological information to verify identity. The basic idea behind biometrics is that our bodies contain unique properties that can be used to distinguish us from others. Besides facial recognition, biometric authentication methods also include:
• Fingerprint scan
• Retina scan
• Voice identification
Facial recognition methods may vary, but they generally involve a series of steps that serve to :-
1. Capture
2. Analyze
3. Compare your face to a database of stored images.
The system can match multiple face prints at a rate of 60 million per minute from memory or 15 million per minute from hard disk.

Applications:
The primary users of facial recognition software like FaceIt have been law enforcement agencies, which use the system to capture random faces in crowds. These faces are compared to a database of criminal mug shots.

Facial recognition software has several other uses:
• Eliminating voter fraud
• Check-cashing identity verification
• Computer security
One of the most innovative uses of facial recognition is being employed by the Mexican government , which is using the technology to weed out duplicate voter registrations. To sway an election, people will register several times under different names so they can vote more than once. Conventional methods have not been very successful at catching these people.

Using the facial recognition technology, officials can search through facial images in the voter database for duplicates at the time of registration. New images are compared to the records already on file to catch those who attempt to register under aliases. The technology was used in the country's 2000 presidential election and is expected to be used in local elections soon.

Potential applications even include ATM and check-cashing security. The software is able to quickly verify a customer's face. After the user consents, the ATM or check-cashing kiosk captures a digital photo of the customer. The FaceIt software then generates a face print of the photograph to protect customers against identity theft and fraudulent transactions. By using facial recognition software, there's no need for a picture ID, bank card or personal identification number (PIN) to verify a customer's identity.

Thus one can say that this software is very useful and can be applied to the many of the important and confidential places.