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Fingerprint



INTRODUCTION


What is A Fingerprint?

A fingerprint is the feature pattern of one finger (Figure 1.1.1). It is believed with strong
evidences that each fingerprint is unique. Each person has his own fingerprints with the
permanent uniqueness. So fingerprints have being used for identification and forensic
investigation for a long time.
Figure1.1.1 A fingerprint image acquired by an Optical Sensor
A fingerprint is composed of many ridges and furrows. These ridges and furrows
present good similarities in each small local window, like parallelism and average width.
However, shown by intensive research on fingerprint recognition, fingerprints are not
distinguished by their ridges and furrows, but by Minutia, which are some abnormal
points on the ridges (Figure 1.1.2). Among the variety of minutia types reported in
literatures, two are mostly significant and in heavy usage: one is called termination,
which is the immediate ending of a ridge; the other is called bifurcation, which is the
point on the ridge from which two branches derive.