The identification or recognition of fingerprints can be very helpful in many different situations. To match fingerprints, a fingerprint scanner can be used. Fingerprint scanners are devices that can authenticate individual fingerprints through several different series of mathematical operations and sensor designs.
Pattern and minutia algorithms can be used in a fingerprint scanner.The pattern algorithm determines the fingerprint's pattern, which can be one of three: an arch, a loop, or a whirl. The minutia algorithm analyzes the fingerprint ridges themselves. This analysis includes ridge endings, or where the ridges end, bifurcation, or where ridges split, and short or dot ridges, which are shorter than the average ridge size.
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A fingerprint scanner can also take the form of one of four different sensors. An optical sensor uses digital imaging to capture the visual image of the fingerprint. A passive capacitance sensor uses pixels to form the image. An active capacitance sensor does the same thing using a charge of electricity, while an ultrasonic sensor uses ultrasonography to form the image.
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The recognition of fingerprints through the use of a fingerprint scanner is a form of physiological biometrics. Biometrics are scientific methods used to identify the unique characteristics or traits of individual human beings. These can include face recognition, iris recognition, fingerprints, DNA, and even a person's unique scent.
Each person's fingerprint has unique features that are only found on that person. Even identical twins do not share the same fingerprints. Though the ridges found in fingerprints function to transmit sensory signals to the brain and to help grip surfaces, they also serve to identify an individual by the unique pattern formations.
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Police stations often use fingerprint scanners to identify victims as well as suspects. High security buildings may use them to grant access to those allowed to enter the building. A fingerprint scanner can even be used in a private home, usually as a security measure to replace a computer access code, or to limit access to certain rooms or containers, such as a safe.
When law enforcement compares fingerprints, they do not rely on overlay images. Instead, they use a more precise method using algorithms to compare two or more sets of fingerprints. If the program detects a significant number of minutia patterns between the two sets of prints, it concludes that they are a match.
Though fingerprint analysis is considered a valuable tool, it is not a perfect system of identification. Some types of scanners, such as the optical sensor scanner, can yield false results. Scanners can also be tricked if a person obtains a copy of another person's fingerprints, and uses them to replace his or her own fingerprints.