The iris is a flat, circular ring-like membrane of the pigmented membrane in the middle layer of the human eye wall, located between the cornea and the lens. The circular portion of the iris that lies between the black pupil and the white sclera can be seen through the cornea, and contains many interlocking speckles, filaments, crowns, stripes, crypts, and other detailed features.
Iris recognition is a biometric identification related to the human eye. It uses an ordinary video camera and does not require close contact between the person and the camera device, which can also be interpreted as a dialog between the eye and the camera.
The uniqueness, stability and immutability of the iris are the material basis on which the iris can be used for identification. Iris recognition technology is also considered to be one of the most secure biometrics in the world.
The color of the iris varies depending on how much pigment it contains and how it is distributed; the only three base colors are brown, blue, and green, and the other colors are variations of these three. Iris biometric device determines a person's identity by comparing the similarity between iris image features centers on the use of pattern recognition, image processing, and other methods to characterize and match the iris features of a person's eyes for automated personal identity authentication.
Each iris contains a unique structure based on features such as crystals, filaments, spots, dimples, wrinkles and stripes. These features determine the uniqueness of iris identification.
While ageing, environmental changes or diseases can affect people's physical characteristics such as fat, thinness, voice, etc., the iris does not undergo any changes as a result. Compared to the human face, its stability is very high.
The iris recognition distance can be close or far, ranging from 10cm~150cm, and in practical applications the industry recommends 50cm~60cm, which is about an arm's length away.
Iris recognition technology can also be added to the pupil tremor and other in vivo detection functions, due to the high cost of forgery and the difficulty of obtaining iris information, iris recognition technology occupies an absolute advantage in the comprehensive security performance, and its security level is currently the highest of all biometric identification technology.
Step 1：Iris image acquisition, where a photograph of the iris is captured through an image acquisition system;
Step 2：Iris localization detection, find out the iris and label the exact position for segmentation from the captured image；
Step 3：The iris image acquired has problems such as translation, rotation, scale change, etc. Before detection, the iris needs to be normalized and unfolded, i.e., the original iris is unfolded to the same size regardless of its size;
Step 4：Iris feature extraction, which is also the most critical step. The texture feature encoding is extracted from the image where the iris localization is completed, and the feature value of the iris is calculated;
Step 5：Matching iris identity, searching the database for iris with or without the same features, so as to achieve the purpose of identity recognition eventually.