What is biometric system ?

It is a technological solution that uses unique physical, physiological or behavioral characteristics of individuals to identify and authenticate them. Biometric systems are employed for various purposes, primarily for security and access control applications.

The technology utilizes following characteristics in order to authenticate or identify the valid individual which include fingerprints, Voiceprints, facial features, Writing patterns, Iris patterns, Hand Geometry etc.

Biometric systems rely on characteristics that are inherently unique to each individual Unlike traditional methods of identification like passwords or PINs, which can be forgotten, stolen, or shared.

How biometric works

Biometric systems typically work by capturing an individual's biometric data through fingerprint sensors or cameras. The captured data is converted into a digital format and then compared it with pre-stored templates or data in a database. If the captured data matches with existing record, the individual is authenticated or granted access.

Biometric System Block Diagram

The figure-1 depicts block diagram of biometric system. It consists of biometric processes.
• Data Collection: The main component is sensor which captures the image of the pattern. This image is compressed.
• Transmission: The compressed image of the pattern is transmitted and stored.
• Signal Processing: The live pattern sample is collected and unique features are extracted using signal processing algorithms. This is compared with the unique features of the image initially stored at the time of enrollment.
• Data Storage: The place of storage for the image samples of many people. This can be harddisk or any other memory types.
• Decision: This is kind of software or hardware or combination of both which compares the live data with the one stored in the database for authentication and verification purpose.

Biometric process flow chart

Biometric Identification Process

The diagram in figure-2 depicts biometric process flow chart. Let us understand how it works with the example of finger print scanning. As shown hardware such as finger scanner captures salient human finger data. The software interprets the resulting data and determines acceptibility.

The finger print is the oldest method of biometrics. It is highly reliable and uses distinctive features of fingers.

A fingerprint image is being read from capture device such as finger scanner. These features are extracted from image. A template is created for comparison.


finger patterns

Following global and local features of finger help in finger print recognition.
➨Global features: Pattern Area, Core Point, Delta, Line Types, Ridge Count, Ridge Patterns
➨Local features: ARCH, LOOP, WHORL
The figure-3 depicts the finger patterns as mentioned above.

There are three stages in this process viz. fingerprint scanning, fingerprint matching and identification. In this type of biometric identification process, acquisition and recognition of person's fingerprint characteristics are used. There are various methods of image capture such as optical, thermal, capacitive, ultrasound etc.

Advantages of Biometric technology

Following are the advantages of Biometric technology:
• No need to remember passwords or PIN numbers while using this technology based applications.
• It provides highest level of security.
• It is highly reliable technology.
• It is used in wide variety of applications such as criminal identification, prison security, credit card security, biometric door locks, weapon activation, ATM, aviation security, border crossing controls, database access etc.

Disadvantages of Biometric technology

Following are the disadvantages of Biometric technology with fingerprint identification or similar image processing technology.
• Need very careful enrollment.
• It has high false reject rate due to pressing too hard, scarring, misalignment or dirt present on fingerprint scanner device.
• Vendor incompatibility in following accurate biometric technology processes.
• There are various cultural issues e.g. physical contact requirement a negative in Japan, privacy issues in North America.
• Presenting fake image patterns to the sensing devices.

Conclusion : This Biometric tutorial is useful for beginners as well as advanced enthusiasts in the field of Biometrics.

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