How does facial recognition work?

February 13, 2022

Facial recognition is a technology that identifies and verifies a human face by analyzing the facial features of an individual through images, video or in real-time and matching the information with a database. It is a biometric identification process in which computer algorithms are used to match specific facial patterns such as distance between the eyes or shape of the chin, etc. The information is then converted into a mathematical formula and compared to the faces in the database to authenticate an individual.

The technology used can vary but the basic functioning remains the same across systems. Here’s how it works:

Step 1: Face detection

A camera captures the image of a face of an individual from a photo or a video or in real-time. The individual could be alone or part of a crowd. Ideally, in the image, the individual looks straight ahead. However, technological advancements allow the software to work even with faces turned in a different angle.

Step 2: Face analysis

The facial recognition software reads the contours of the captured face. Most of the software prefer 2D images instead of 3D since they are easier to match with those in the database. It then identifies different facial landmarks — also known as nodal points — such as distance between the eyebrows, shape of the nose or the cheekbones, etc.

Step 3: Converting the image into data

Once the face has been analyzed, the information is turned into a mathematical formula with each nodal point becoming a number code. All the codes are together fed into the database as a unique faceprint, similar to a unique thumbprint.

Step 4: Finding a Match

The faceprint is then compared with millions of images from the database. The software tries to match the image with one having the exact facial features. If a match is found, then the user is authenticated with relevant information such as name, address, etc.

Purpose of facial recognition

Facial recognition is generally used for an application, a system or a service. It is vastly used for security by the police to identify miscreants. However, currently, it is used for multiple other purposes, such as:

• Device security: Unlocking apps and smartphones
• Airlines: Identification by customs; biometric check-in by airlines
• School security: Attendance in class and during exams; as a security shield against offenders
• Shoplifting: Identifying shoplifters and marking them as threats
• Entertainment: Making funny filters like how one would look in old age, etc.
• Marketing: Spotting target groups based on gender, age, ethnicity, etc. to push a product

Facial recognition is here to stay for the long haul and we are still at the tip of the iceberg. The technology is growing by leaps and bounds with multiple upgrades to make it more reliable and secure. It is just a matter of time until facial recognition becomes a part of our daily lives.