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Published byEstella Gibbs Modified over 9 years ago
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Finger print classification
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What is a fingerprint? Finger skin is made of friction ridges, with pores (sweat glands). Friction ridges are created during fetal live and only the general shape is genetically defined
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Primates also have fingerprints
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So do koalas!
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General Characteristics – macro- singularities Loops Whorls Arches
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Arch
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Tented Arch
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Loops Left loop Right loop
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Double loops
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Whorl
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Type lines
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Ridge lines often flow in parallel producing features called whorl, loop and delta
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The ridge-line flow can be described by a directional map (or directional image) which is a discrete matrix whose elements denote the orientation of the tangent to the ridge lines.
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Minutiae Minutiae play a primary role for fingerprint matching, since most of the algorithms rely on the coincidence of minutiae to state whether two impressions are of the same finger or not. Minutiae matching, which is essentially a point pattern matching problem, constitutes the basis of most of the automatic algorithms for fingerprint comparison.
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Types of minutiae
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Micro-singularities, called minutiae or Galton characteristics, are determined by termination or bifurcation of the ridge lines.
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Fingerprint minutiae Bifurcation, ridge ending, core, delta
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Deltas
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Fingerprint matching – finding points of correspondence
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Accidental – unusual combinations
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Scars produce unusual patterns
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Some skin conditions can produce altered fingerprints
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Twins have different fingerprints: overall pattern is similar, differ in fine details
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