What's the science behind fingerprint scanners?

Bio-metrics are automated methods of recognizing a person based on a physiological or behavioral characteristic. Among the features measured are face, fingerprints, hand geometry, handwriting, iris, retinal, vein, and voice.

The scanner uses a light-sensitive microchip, either a CCD, charge-coupled device, or a CMOS image sensor, to produce a digital image. The computer analyzes the image automatically, selecting just the fingerprint, and then uses sophisticated pattern-matching software to turn it into a code.

The technique relies on capturing an optical image, essentially a photograph, and using algorithms to detect unique patterns on the surface, such as ridges or unique marks, by analyzing the lightest and darkest areas of the image.

allowed for the prediction of the properties of missing elements.