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Exemplar Marking Image : An Analysis Of A Search For A Fingerprint Image

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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 …show more content…

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

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