The principle of face recognition, the principle of face recognition

In fact, the machine is not good at recognizing images, for example, this ** is just a string of 0 and 1 data in the eyes of the machine, and the machine cannot understand the meaning of this image. So if we want the machine to learn to recognize images, we need to write programs and algorithms for it.

When we describe a person's appearance, most of us will use words like this, such as melon seed face, willow leaf eyes, garlic nose, and cherry mouth. The so-called appearance largely depends on the shape of the person's head and facial features.

The earliest facial recognition was based on such a method. First, the machine will recognize the location of the face in the image, and then draw the outline of the facial features on this face, and obtain the shape and position information of the facial features on the human face. For example, the distance between the two eyes, the angle of the line connecting the tip of the nose and the corner of the mouth in the horizontal direction, etc.

The principle of face recognition is to use a camera or camera to collect images or streams containing faces, and automatically detect and track faces in the images, and then perform face recognition on the detected faces. Face recognition is a biometric technology based on human facial feature information for identification, and its essence is image processing.

When the machine or mobile phone performs image processing, it is necessary to check the geometry of the facial organs and the distance between the organs, and after completing the above operations, it is then compared with the facial features entered for the first time, so as to achieve successful information authentication and mobile phone unlocking.

Traditional facial recognition technology.

It is mainly based on face recognition based on visible light images, but this method has insurmountable drawbacks, especially when the ambient light changes, the recognition effect will drop sharply, and it cannot meet the needs of the actual system.

After the development of science and technology, face recognition technology is a multi-light source face recognition technology based on active near-infrared images. It can overcome the effects of light changes and has achieved excellent recognition performance, surpassing 3D image face recognition in terms of overall system performance in terms of accuracy, stability, and speed. This technology has developed rapidly in the past two or three years, making face recognition technology gradually become practical.

The face recognition system generally refers to the facial recognition access control system, which is based on advanced facial recognition technology, combines mature ID card and fingerprint recognition technology, and innovatively introduces a biometric access control system for safe use.

The face recognition system is based on advanced facial recognition technology, combining mature ID card and fingerprint recognition technology to revolutionize the safe and practical biometric access control system. The system is practical and secure through the collection of face, fingerprint, ID card information and biometrics, and the separation of inside and outside access control. The system uses encrypted transmission of network information to support remote control and management, and can be widely used in access control security control in major areas such as banks, military, public security, and intelligent buildings.

How does a facial recognition system work?

The regional feature analysis algorithm widely used in face recognition technology integrates computer image processing technology and biostatistical principles, uses computer image processing technology to extract character feature points from **, and uses biostatistical principles to analyze mathematical models, that is, facial feature templates. Using the completed facial feature template, the subjects were analyzed for facial images and features, providing similar values based on the results of the analysis. This value can be used to confirm whether it is the same person.

What are the functional modules of the face recognition system?

Facial capture and tracking capabilities.

Facial capture refers to the detection of an image in a frame of an image or ** stream, and the separation of the image from the background and automatic saving. People tracking is the use of person capture technology to automatically track a specified person as it moves within the camera's shooting range.

Compare facial recognition.

There are two comparison modes: facial recognition verification and search. The verification ceremony refers to the comparison of a captured or specified portrait with a pair registered in the database to confirm that it is the same person. Searching for a match in a ritual is a search among all the people registered in the database to find out if there is a specific persona.

Facial modeling and retrieval.

You can model the checked-in person data, extract facial features, and save the resulting facial templates (facial feature files) in the database. When performing a face search (search method), a specified persona is modeled, then identified with a template of all the people in the database, and finally a list of the most similar people is made based on the matching similarity values.

Commonly used biopsies include binocular cameras, 3D structured light, etc.

Image quality checks.

The quality of the image directly affects the effect of recognition, and the detection function of image quality evaluates the image quality of the first image to be compared, and provides appropriate recommended values to help recognition. Originally written by Hanma Wisdom.

Facial recognition technology.

The principle of face detection face recognition technology does not sound profound, it recognizes the eyes, mouth and other feature information in the picture, locks the position of the face in the picture, and automatically takes the face as the subject of the shot, and sets the accurate focal length and the amount. When the face detection function starts to work, the camera will automatically set it according to the position and illumination of the face in the frame to ensure that the face is clear and accurate. In addition, when there are multiple people in the frame, Face Detection works accurately to pick the most important object.

How to implement facial recognition technology.

In previous shoots, how to deal with the relationship between the subject and the background has been a troublesome problem: if the subject is not in the middle of the viewfinder, the camera may focus on the distant background, causing the subject to blur; When there is a large difference in the brightness of the person and the background, it will cause the face to be insufficient or excessive. In order to solve these problems, professional digital cameras are equipped with a "5-point, 9-point" focusing system and a "surface metering, spot metering, and bracketing metering" metering system, and also add "AE AF lock".

Such a complex setup is a huge test of experience and finger dexterity for many digital cameras that don't have these features. The advent of face recognition technology has made this problem no longer exist. This technology allows the camera to automatically recognize whether there is a person's face in the frame and automatically take the face as the subject of the shot.

The camera will then be adjusted for the condition of the face in terms of focus and control.

This smart feature brings two of the most immediate benefits: first, it allows the photographer to concentrate more on framing, which can achieve a more perfect composition; The second is to improve the speed of shooting. For example, Fujifilm's Face Detection face recognition function is based on hardware, that is, there is a special integrated circuit in the camera's processing chip to carry out calculations, and the processing time is less than seconds, which is much faster than the previous process of "aiming at the subject, pressing the shutter halfway, pressing the AE AF lock, framing", and is more suitable for the needs of capturing.

Face recognition refers to:Face recognition is a biometric technology that recognizes people based on their facial features. A series of related technologies that use cameras or cameras to collect images or streams containing faces, and automatically detect and track faces in the images, and then perform facial recognition on the detected faces, are also commonly called portrait recognition and facial recognition.

Technical characteristics of face recognition:1. Non-mandatory: Users do not need to cooperate with face acquisition equipment, and can obtain face images almost unconsciously, and there is no "mandatory" sampling method.

2. Non-contact: Users do not need to be in direct contact with the device to obtain face images.

3. Concurrency: In actual application scenarios, multiple faces can be sorted, judged and recognized.

Although face recognition access control is a very technological product in the eyes of ordinary people, its working principle is very simple. To sum up, it is the four steps of face collection, modeling and storage, face comparison, and identity verification, and the following is a detailed breakdown of its working principle, hoping that you can have a clearer understanding of face recognition access control.

The first is face collection. As with facial recognition on mobile phones, the first step is to capture your face. When you enter face data for the first time, you need to collect the front, left and right sides of your face through the camera.

This is the current common practice of face recognition access control, and the optimized face recognition access control is different, it not only supports on-site face recognition data collection, but also supports the upload of face recognition data by the user terminal, and then through the administrator background review can complete the first entry of data.

Then there's the modeling store. When the face data collection is completed, it will be processed by the back-end system, such as extracting the features of the face, digitally modeling, and encrypting and storing it in the database to generate an index. And bind all the information belonging to this person, such as name, address and other information, to facilitate the management of the property company and grid personnel.

Then there's the face comparison. As mentioned earlier, after doing a good job of modeling and storing and generating an index, you only need to walk in front of the face recognition access control, and the camera will dynamically track and sample and generate feature data, and then match the data in the comparison library to quickly confirm the identity of the person and display the relevant information bound to the person. In addition, in the early days of the application of face recognition technology to mobile phones, there have been cases of using ** to deceive the face recognition system and successfully unlock the mobile phone.

In the final analysis, this is just a problem of algorithms, at present, in addition to mobile phones, face recognition access control also uses 3D facial recognition technology, which can judge whether it is a real person or **, which effectively solves this embarrassing problem.

It is worth mentioning that the face recognition access control has the characteristics of contactless, and can be equipped with infrared temperature measurement modules to realize batch detection of body temperature and complete identity verification, which has played an important role in the current epidemic prevention and control. For example, the "digital sentinel" face recognition health code identity verification all-in-one machine launched by Hanma Wisdom can greatly simplify the daily epidemic prevention process. I also hope that in the future, face recognition can serve more people and let more people experience the convenience brought by high technology!

The principle of face recognition is to scan, analyze and record facial contours, face geometry, etc., so as to distinguish subtle differences.

When the camera collects our facial information, we need to process our faces, because when we enter facial information, the environment in which we are located cannot be without changes, and the changes in the environment will affect the difficulty of face recognition, so the images must be processed, so that the machine or mobile phone can recognize our facial information and realize the unlocking of the mobile phone.

When the machine or mobile phone performs image processing, it is necessary to check the geometry of the facial organs and the distance between the organs, and after completing the above operations, it is compared with the facial features we entered for the first time, so as to achieve successful information authentication and mobile phone unlocking. The twins can't be distinguished by the naked eye, but face recognition technology can, even if two people are very similar, but the living environment, personality characteristics, inner thoughts and ways of doing things are different for two people.

Advantages of Face Recognition:

Face recognition technology is based on the facial image of the person, and the face is undoubtedly the most intuitive source of information that can be judged by the naked eye, which is convenient for manual confirmation and auditing, and "judging people by appearance" is in line with the laws of human cognition. Compared with other biometric technologies, the recognition accuracy of face recognition technology is at a high level, and the false recognition rate and rejection rate are low.

Face recognition technology uses a general-purpose camera as a device to obtain recognition information, and completes the recognition process in a non-contact manner without the recognition object being aware of it. In applications with high security requirements, face recognition technology requires that the identified object must be present at the identification site, and it is difficult for others to counterfeit it. The unique activity discrimination ability of face recognition technology ensures that others cannot deceive the recognition system with inactive **, puppets, and wax figures.

This is something that is difficult for biometric technologies such as fingerprints to do.