How Fingerprint Recognition Technology Works in Our Devices ?

Biometrics have taken a long flight in the attendance system in this rapidly growing era of technology. Biometrics is the identification of a person based on his intrinsic characteristics, such as voice, fingerprint, iris, face and hand geometry, etc. But the most famous biometric characteristics used in attendance devices are fingerprint recognition. Fingerprint recognition is one of the most popular biometric techniques used in automatic personal identification and verification.

The use of biometrics has revolutionized the technology and level of security, wherever the biometric devices are installed. But in the course of design and development of biometric devices, the use of fingerprint recognition technology is used.

StarLink India uses the “Fingerprint Recognition Technology"StarLink India uses the “Fingerprint Recognition Technology” for verification process in its devices. During this matching process we use minutiae matching for finger verification with its template. But again the question arises, how does the template is formed? And what is minutiae matching?

Let us discuss all about the process of fingerprint template formation and minutiae matching. May be the step will seem very complex, but this whole process takes place in milliseconds.

The fingerprint is captured through optical sensor, which takes the mono-chrome image of finger print in 8bit-grayscale. Then, the 8 bit grayscale images are converted into 0&1 depending on the permutations & combinations of the nearby pixels. This is decided by running an algorithm.

Initially the image of a fingerprint that is captured by optical sensor accompanied by the CMOS sensor is in grayscale, which is not so clear. The image is filtered based on FIR (Finite Impulse Response) is used to convert the gray scale images into single thin line and as a result sharp image of fingerprint pattern is formed. Undirected lines are removed and each cut marks and unwanted marks are removed and the ridges are joined for the perfect pattern.

After this process, Gabor filter is used, which forms the 4X4 block of pixel. Then, points are marked on valleys, ridges, bifurcations and deltas. Then its 15-20 minutiae are marked in X-Y axis, including the direction of the minutiae. A unique pattern is formed by matching minutiae with its directions. Thus, the image formed is a final fingerprint template which is an array of minutiae of 240x320 pixels in the range of 200-500 byte.

Now templates of fingerprints are stored in the memory of the device. After the storage of template, whenever anyone punches, the templates stored is matched with his fingerprint. The matching is done on the basis of “matching score”, which is fixed by the admin. We have to take care while deciding the Matching score, because the FALSE ACCEPTANCE RATE increases with decrease in security score, whereas FALSE REJECTION RATE increases when security score increases.

The fingerprint matching is done in Our Devices on the following methods:-

1:1 matching: In this method, employer shows their attendance card (which holds it details), then a message comes off “Put finger”. So when he shows the ID, the finger template is stored against his name is matched with the fingerprint he is punching. And after which message of success or failure comes. It is very fast matching method which takes less time; and this method is perfect for the workplace of more than 1000 employees.

1:N matching: In this method, the employee punches and his fingerprint are matched with the total number of templates stored in the device and depending on the matching score, the success or failure rate is decided. This method is perfect for the work place of less than 1000 employees as it takes more time than the previous one.

All this process is handled by a dedicated DSP (Digital Signal Processor) running at 400 MHz speed in StarLink's Devices.

Although it may appear to be a simple process, fingerprint recognition involves the state-of-the-art technology in hardware, for the readers, and software, to process the fingerprint images and templates. But due to the effort of our hardware and software team, all this complexity is hidden and fingerprint technology usage is nowadays as simple as touching the reader.

StarLink has expertise in manufacturing and designing the fingerprint system according to the requirements. So if you want to consider this technology and want a flawless operation of your biometric devices, then StarLink will certainly help out with best device.