Introduction to Face Recognition Technology

Face recognition (Face Recognition) is a biometric technology that automatically performs identity recognition based on a person's facial features (such as statistical or geometric features), also known as face recognition, portrait recognition, face recognition, face recognition , Facial recognition, and more. Generally speaking, face recognition is short for identity recognition and verification based on optical face images.

Face recognition uses a camera or camera to collect images or video streams containing faces, and automatically detects and tracks faces in the images, and then performs a series of related application operations on the detected face images. Technically, it includes image acquisition, feature location, identity confirmation and search, and so on. In simple terms, it is to extract the features in the face from the photo, such as eyebrow height, mouth corners, etc., and then output the results by comparing the features.

Face recognition

The general process of face recognition:

1.Face collection

Different face images are collected through the camera lens, such as still images, dynamic images, different positions, different expressions, etc. When the collection object is within the shooting range of the device, the collection device will automatically search for and capture the face image.

2.Face detection

Accurately mark the position and size of the face in the image, and pick out useful information (such as histogram features, color features, template features, structural features, and Haar features), and then use the information to achieve face detection purpose.

3.Face image preprocessing

Based on the results of face detection, the image is processed and finally serves the process of feature extraction.

Because the original image obtained by the system is limited by various conditions and random interference, it can not be used directly. It must be pre-processed such as grayscale correction and noise filtering in the early stage of image processing.

The components of a face recognition system

4.Face feature extraction

Features that can be used in a face recognition system are generally divided into visual features, pixel statistical features, face image transformation coefficient features, face image algebraic features, and so on. Face feature extraction is based on certain features of the face, also known as face representation, which is a process of feature modeling of the face.

5. Matching and identification

The extracted facial feature value data is searched and matched with the feature template stored in the database. By setting a threshold, the similarity is compared with this threshold to judge the identity information of the face.