1.1 Marking Process
For a thoroughly refined fingerprint image, there are only three kinds of ridge points: (1) Cn (P) = 1, Sn (P) = 1, called end point; (2) Cn (P) = 2, Sn (P) = 2,3,4, called continuous point; (3) Cn (P) = 3, Sn (P) = 3, called fork. (P, P1, P2, ⋯, Pn), where n is the number of extracted feature points, Pi = (Xi, Yi, Ti, Ai), Xi, Yi denotes the feature point Ti represents the type of the feature point, when the feature point is the end point Ti = 1, when the feature point is the end point Ti = 2; a represents the angle of the feature point, the endpoint angle from the end point as the starting point of the end line, Point angle of Figure 2.3 (b) in the angle a, b, c the smallest of the relative branch of the angle. The
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At present, the extraction algorithm for fingerprint direction information is Mehtre, L.Hi made by. Which Mehtre proposed based on the neighborhood of the template in different directions to change the gray value of the point direction, and then statistics of the block direction of the method. This method is simple, but it is less effective for regions with singular points. L. Hong et al. proposed a method of obtaining a pattern using gradient operator, which obtains the direction information of the fingerprint image by examining the gradient change of the fingerprint image, and the direction is continuous angle Meticulous representation of the true direction of the text information, but the algorithm is relatively complex. Since the fingerprint pattern we want to be passed as an important parameter to the next direction of the filter, so the choice of the literature method. The specific algorithm is as follows:
(1) The fingerprint image is divided into 16 × 16 non-overlapping small pieces.
(2) Calculate the gradient of each pixel (i, j) in the x-axis direction (u, v) and y The gradient in the direction of the axis (u, v).
(3) Calculate the block direction based on the gradient value (i, j) as the center of the block direction, the formula
Measure the side length of each block along the grain. When taking a measurement, position the block so the caliper measuring surfaces are touching the end grain faces. Record the measurements to create a data set. Accuracy =.001 in
In quadrants 1 and 2 how the amount and constituents of the fingerprint residue on the substrate affects the fingerprint image, is determined. In quadrant 1, excess sebum and moisture is first removed from the finger tips with the help of a clean cloth. In quadrant 2, fingertip is first wiped around the nose or forehead to create excess sebum. Quadrant 3 and 4 were used to compare the details between untreated and dusted fingerprint residues.
Minutia points represent positions where friction ridges end abruptly or where a ridge branches into two or many more ridges. A typical good-quality fingerprint template contains 20-70 minutiae points; the actual number depends on the size of the finger sensor surface and how the user places his or her finger on the sensor. The system stores the minutiae information position and direction along with the user's demographic information as a template in the enrollment database.
Lee, H. (2001). Advances in Fingerprint Technology, Second Edition, 2nd Edition. Retrieved January 26, 2015, from Vital Source: http://online.vitalsource.com/books/9781420041347
After Galton’s discovery, the use of fingerprinting by law enforcement was inevitable. In 1892, an Argentine police official, Juan Vucetich, became the first person to identify a criminal through fingerprints (The History of Fingerprints). The last major step necessary for the widespread use of fingerprint identification was to create a classification system that simplified the process of matching fingerprints. That came in 1901, when Edward Henry devised a system that separated fingerprints into four different categories - loops, whorls, arches, and composites (Skopitz). Shortly after its development, most European nations implemented this system of
samples of an individual’s fingerprint’s can be lifted from a crime scene. The breakthrough of
Fingerprint comparison has always interested me because of the uniqueness in friction ridge detail. As a fingerprint expert, you learn that there are no two individual in the world that have the same fingerprints. Individuals can share the same DNA but their fingerprints will always be different. Examiners may be able to find two fingerprints that have many of the same characteristics, but not exactly the same as in the case of the Madrid bombing. The basics of fingerprint comparison will always be the same. However, it fascinates me how procedures change, and make fingerprint comparison more of a science.
The final main biometric technology used is fingerprint recognition. This is definitely the most widely used biometric technology. This type of biometric has been used for many, many years. Because of this, fingerprint recognition has been known as the most primary and accurate identification method used to identify a person. The modern fingerprint recognition is all done electronically. There are two main ways of analyzing fingerprints electronically. The first plots points on the ridges of a person’s fingers that enable the computer to compare to different fingerprints. The second method uses patterns of a fingerprint
The automated Fingerprint Identification System is also known as the AFIS within the law enforcement division (FBI, 2010). This system is an important element in the criminal justice system as some of its features encompass the storing of data, encoding, and fingerprint and facial comparison through graphics and other techniques. Law officials many centuries ago in the pursuit of positively identifying someone suspected of guilt have long used fingerprints techniques. Fingerprinting is also used in branches of our government, and in the Pentagon, the authentication method of fingerprints is used permit access to specified zones inside the building. Fingerprints are an effective and very precise method of identification purposes that does not pose
“Fingerprint recognition is one of the divorce inference using the impressions made by the minute ridge formations or patterns found on the fingertips. No two people have exactly the same arrangement of the ridge patterns, and the remaining patterns of any one individual unchanged. Fingerprints infallible provide a means of personal identification. Other personal characteristics may change, but not fingerprints”. (1)
Fingerprints, known for each person to have unique ones, are made of a series of ridges and furrows on the
Every time somebody touches something, they leave behind a unique signature that forever links them to that object. This link is their fingerprints, which are unique to every person, for no two people have the same set, not even family members or identical twins. Palms and toes also leave prints behind, but these are far less commonly found during crime scene investigations. Therefore, fingerprints provide an identification process that is applicable to background checks, biometric security, mass disaster identification, and most importantly, crime scene investigations. Fingerprints are so differentiated because they are made up of distinct patterns of ridges and furrows on the fingers. The ridges are the “raised” portions of the prints, and the furrows are the “recessed” portions. This perceived uniqueness has led some people to falsely accept fingerprint analysis as absolute scientific fact. Although overall fingerprints are reliable, there are definitely situations where their accuracy can come into question.
Capacitive sensors use an array capacitor plates to image the fingerprint. Skin is conductive enough to provide a capacitive coupling with an individual capacitive element on the array. Ridges, being closer to the detector, have a higher capacitance and valleys have a lower capacitance. Some capacitive sensors apply a small voltage to the finger to enhance the signal and create better image contrast.
Personal verification is the major concern because of its wide usage in many applications. Recently, hand based biometrics technology is being used in many applications and also involved the significant attention of the individual towards biometric system. Hand based biometric system presents many types of recognition by means of fingerprint, palmprint, hand geometry and hand vein. Biometrics is broadly classified and referred in two aspects for authenticating the individuals namely,
The obtained image is applied to a thinning algorithm and subsequent minutiae extraction. The methodology of image preprocessing and minutiae extraction is discussed. The simulations are performed in the MATLAB environment to evaluate the performance of the implemented algorithms. Results and observations of the fingerprint images are presented at the end.