Introduction to Fingerprints
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Transcript of Introduction to Fingerprints
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Why Do We Have Fingerprints?
Dermal Papillae: an undulating sub-layer that causes friction ridges
Why Do We Have Fingerprints?
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Friction Ridges allow us to hold on
to things more easily.
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Fundamental Principlesof Fingerprints
They don’t change.
Can be classified by their ridge patterns
Unique because of minutiae
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3 Types of Ridge Patterns
o Loops•Whorls•Arches
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Loop
one or more ridge enters and exits from the same side. Loops must have one delta (triangular area).
Types Radial: opens toward the thumb Ulnar: opens toward the “pinky”
(little finger)
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Whorl
at least one ridge makes a complete circuit.
Types Plain Central Pocket Double Loop Accidental
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Arch
has ridges that enter on one side, rises in the middle, and ends on the other side
Types Plain Tented
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3 Types of Ridge Patterns
o Loops: most common pattern (65% of people have these)
• Whorls: 30%• Arches: least common pattern (5%)
Individual fingers can have different ridge patterns!
Galton: observer of minutiae
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Minutia: small patterns in the print
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Examples of Minutia
RIDGE ENDINGBIFURCATION
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More Minutia Examples
SHORT RIDGEISLAND
ENCLOSURE