Facial recognition and identity verification: How does it work?

by | Mar 12, 2024 | À la une, Identity check

Facial recognition and identity verification are increasingly ubiquitous technologies in our daily lives. These tools recognize and verify the identity of individuals. To do this, they rely on their unique facial characteristics. Let's dive into the world of identity verification in the age of facial recognition.


How facial recognition works


Facial recognition is based on a set of sophisticated technologies. These capture, analyze and identify an individual's unique facial features. To understand how it works, it's essential to know the basics of this technology, which we'll now cover.


Fundamental concepts of facial recognition


Facial recognition uses computer vision and image processing concepts for face detection. In this way, it is possible to identify a face in an image or video. This technology relies on the ability of tools to recognize patterns and structures in human facial features. For example: eyes, nose, mouth and facial contours.


Operating principles


Facial recognition involves several key steps. First, the system must detect the presence of a face using face detection algorithms. Next, it analyzes the facial characteristics of the detected face, such as the shape of the eyes and the distance between them. In this way, it can construct a digital representation called a "faceprint". Finally, it compares this faceprint with another, stored in memory, to identify the corresponding person.


Facial recognition, authentication and identity verification


It's important to distinguish between facial recognition, authentication and identity verification.

  • Facial recognition involves identifying a specific face in an image or video. In a way, it's how identity authentication and verification work.
  • Authentication checks whether the face identified corresponds to that of a person already known, present in a database, in order to authorize access to the account. Authentication can use facial recognition, as with Face ID to unlock your iPhone.
  • The aim of identity verification is to ensure that a virtual user is the physical person he or she claims to be. The aim here is to provide an online service while limiting the risk of fraud.

These distinctions are essential to understanding the role of facial recognition in identity verification.


The facial recognition process


The facial recognition process is a complex sequence of steps that capture,analyze andidentify an individual's facial features.


Detailed steps: from capture to verification


Facial image capture

The first step is to capture an image or video containing the face of the individual to be authenticated. This can be done using surveillance cameras, security cameras, webcams or even smartphones.


Human face detection

Once the facial image has been captured, the facial recognition system uses face detection algorithms to locate and extract the facial region from the image. This step is crucial to isolate the face from the background and other image elements.

face detection - détection du visage

At this stage, a box is placed around the detected faces.


Biometric data extraction

After detecting the person's face, the system analyzes its facial features (mouth, eyes, spacing, etc.). These are extracted from the image and converted into digital data uniquely representing the face.


Faceprint creation

A mask is then constructed from the characteristics of the face, known as a faceprint.

facial recognition features

From the extracted facial features, the system creates a "faceprint". A digital faceprint that uniquely represents the individual's identity. This "faceprint" can be used in computerized form.

  • In the case of biometric authentication, the facial mask is compared with those stored in databases. If the user is identified, they can access their account or unlock their device.
  • For identity verification, the faceprint is compared with an official document containing a passport photo. If these two elements match, the user's digital identity is validated.


Facial recognition algorithms


Face detection algorithms

Face detection algorithms are designed to locate and extract faces in an image or video. They use a variety of techniques. Among the most important: edge detection, image segmentation, deep learning and machine learning. These algorithms are essential for isolating the face from the background and other image elements. This facilitates subsequent analysis of facial features.Artificial intelligence anddeep learning tools make photographic recognition processes highly reliable and reduce error rates.


Facial feature analysis algorithms

Once the face has been detected, facial recognition algorithms analyze facial features. They use a combination of image analysis and feature extraction techniques. For example:

  • Discrete cosine transform (DCT ), which extracts local regions of the face.
  • Fourier transform, useful for visual recognition of facial shapes.
  • Convolutional neural networks (CNN ), to analyze each pixel in its environment (image below).

convolutional neural network for image recognition

These facial analysis techniques extract precise information about facial features.


Why does identity verification need facial recognition?


Identity verification is an essential component of many processes. Whether accessing online services, crossing borders or carrying out financial transactions. Facial recognition offers several major advantages in this field. It enhances the security, accuracy andefficiency of identification processes to effectively combat fraud.


Advantages of facial recognition for identity verification


Increased reliability

Facial recognition technology offers greater reliability in identity verification. It is based on unique biological characteristics, specific to each individual. Facial recognition thus offers optimum security. It provides a robust check that is difficult to falsify.


Speed and efficiency

Facial recognition enables fast, efficient identity verification. This reduces waiting times and friction in the identification process. Thanks to sophisticated algorithms and advanced image processing technologies, facial recognition can identify individuals in just a few seconds. This facilitates online registration and transactions.


Ease of use

Facial recognition is an easy-to-use identification method. It requires no specialized equipment or special technical knowledge. Users can simply present themselves in front of a camera to be identified.


Versatile application

Facial recognition algorithms can be used in a variety of contexts and industries. From online banking to border security and building access control. Their versatility makes them an ideal solution for diverse identification and identity verification needs.


Improved precision

Thanks to technological advances in artificial intelligence and machine learning, facial recognition offers a high level of accuracy. Facial recognition algorithms are able to recognize faces with impressive accuracy. Even in varying lighting conditions or with different viewing angles.


The business impact of facial recognition


Reducing the risk of fraud

By providing more robust identification that is harder to forge, facial recognition helps reduce the risk of fraud andidentity theft. Companies can thus improve their protection against fraudulent activities, terrorist financing and money laundering.


Enhanced safety

Facial recognition enhances security by providing an identification method that is difficult to steal. The security of companies and individuals is thus strengthened in the face of identity theft and document forgery.


Increased efficiency

By automating manual tasks, facial recognition identity verification systems reduce the risk of human error. Facial recognition systems can be integrated with existing applications and systems to simplify workflows and speed up transactions.


Increased customer satisfaction

Facial recognition allows us to optimize our customercontact processes. File processing time is greatly reduced. As a result, customers can take advantage of the company's services without having to wait or travel.


Facematch: facial recognition from a photo


Photo-based facial recognition is also known as "facematching". It's a method of identity verification that uses a photo of a face to identify the individual. This approach is based on the comparison of a selfie taken using a smartphone, with the photo present on an identity document. Here's a detailed analysis of the facematch concept, methods for avoiding photo-based fraud, and its advantages and limitations.


Explanation of the facematch concept


From a photo portrait, facial recognition algorithms analyze the distinctive features of the face. Contours, proportions and many other elements are identified. This enables the portrait to be compared with a photo from an ID document. Once these images have been compared, the AI is able to give a confidence rating that the 2 images come from the same person.


Methods used to prevent photo-based fraud


To prevent photo-based fraud, facematch systems use various security and verification techniques. These include photo authenticity analysis. This can include the detection of facial depth and relief to distinguish 2D images from real 3D faces.


Facematch benefits for facial recognition


Ease of use

Photo-based facial recognition is simple and convenient to implement. All you need is a passport photo and a selfie to verify a person's identity.



Results can be obtained quickly (or even instantly), reducing friction with the user.



This method can be used in a variety of contexts. These range from mobile applications to ATMs and security systems.


Facematch facial recognition limits


Vulnerability to fraud

Identity photos can be falsified or obtained without consent. This makes facematch vulnerable to certain frauds and scammers, who manage to fool the system.


Reduced precision

Photo-based facial recognition can be less accurate than other methods. This is particularly true if the photos are of poor quality, or if the faces have different angles or expressions.


Dependence on image quality

The quality of the image used is crucial to the reliability of the facematch. This can influence facial recognition results. Performance may vary according tolighting, resolution and other environmental factors.


Liveness : Proof of life video


Liveness, in the context of facial recognition, refers to the ability to detect whether a face is actually present and moving. This feature is essential for enhancing the security and reliability of facial recognition systems. Liveness guarantees that identification is made with a living person.


Definition of liveness check in the context of facial recognition


Liveness certifies a person's liveliness by means of a video. Rather than a simple static image, the user is asked to film certain movements to confirm his or her identity. This is also known as proof-of-life or life detection. This technology enables the verification of biometric signals such as eye blinks, head movements, facial expressions and so on.

Usually, a frame of the video is also retrieved for facematch verification. In this way, liveness adds a layer of security to identity verification.


Detecting proof of life from video


To detect proof of life from video, facial recognition systems use a variety of methods and technologies. These include eye movement analysis. Eye blinks and pupil movements are, in this case, indicators of liveliness. In addition, the detection of head movements, facial expressions and changes in posture can be used to detect liveliness.


The importance of liveness in online identity verification


Liveness is of crucial importance in online identity verification. It enhances the security and reliability of identification processes. It ensures that the face subjected to facial recognition is not a mere material representation. Liveness thus helps prevent fraud based on pre-recorded photos or videos.

It also ensures that users are truly present and engaged in the identification process. In this way, online transactions and digital interactions are secure.

Ultimately, liveness check helps to ensure accurate, reliable and secure identity checks.


Further information: Facial recognition is not enough


Although facial recognition is a powerful technology for identity verification, it alone is not enough to guarantee total security against fraud. To effectively combat fraudulent activities, it is essential to implement information verification and document authentication.


Checking information


Verifying information involves comparing the personal data provided by the user. These include, but are not limited to, surname, first name, date of birth and address. It also includes salary status, salary amount, political affiliation, etc.

This step ensures that the information provided is valid and consistent by cross-referencing the information. In this way, the risks ofidentity theft or document fraud are minimized. Robust verification processes, such as comparing the information supplied with reliable external sources, can help to enhance security. Read our article on combating document fraud.


Document authentication


Document authentication consists of verifying theauthenticity of identity papers and documents supplied by the user (passports, ID cards and driving licenses). This step ensures that the documents submitted are legitimate and not falsified. This reduces the risk of fraud andidentity theft.

Advanced authentication techniques can be used to guarantee the legitimacy and validity of documents. These include verification of holograms, signatures and document security features. Several articles on document authentication are available on our website. Find out more about identity card control points. See also our article on how toidentify a forged passport.


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