3. Fingerprint Patterns
Arch- The ridges enter from one side of the finger, rise in
the centre forming an arc, and then exit the other side of the
finger.
Loop-The ridges enter from one side of a finger, form a
curve, and then exit on that same side.
Whorl-Ridges form circularly around a central point on
the finger.
Arch Loop Whorl
6. Different Identification on Fingerprint
Crossover: two ridges cross
each other
Core: centre
Bifurcation: ridge separates
Ridge ending: end point
Island: small ridge b/w two
spaces
Delta: space between ridges
Pore: human pore
8. Fingerprint matching techniques
There are two categories of fingerprint matching techniques:
1. minutiae-based .
2. correlation based.
Minutiae-based techniques first find minutiae points and then
map their relative placement on the finger.
The correlation-based method is able to overcome some of the
difficulties of the minutiae-based approach.
9. Two main technologies used to capture image of the fingerprint
Optical sensor – use light refracted through a prism. An optical sensor
based reader uses light to read and acquire fingerprint images. Optical
sensors can be affected by a number of real life factors such as stray
light, surface contamination or even prior fingerprint impressions
present on the sensor surface. Hence it is essential to clean the
fingerprint reader glass on a regular basis for optimal performance.
Capacitive sensor – detect voltage changes in skin between ridges and
valleys. Capacitive sensors use electric current to sense a fingerprint
and capture the image. As sensors apply a small voltage to the finger, a
real fingerprint is required rather than a visual impression of it. This
technique makes the fingerprint reader more reliable as it becomes
harder to fake enrolment.
10. Image Processing
Capture the fingerprint images and process them through a series of
image processing algorithms to obtain a clear unambiguous skeletal
image of the original gray tone impression, clarifying smudged
areas, removing extraneous artifacts and healing most scars, cuts and
breaks.
14. Advantage of Fingerprint:
a. Very high accuracy.
b. Is the most economical biometric PC user authentication technique.
c. Easy to use.
d. Small storage space required for the biometric template, reducing the
size of the database memory required
e. It is standardized.
Disadvantage of Fingerprint:
a. For some people it is very intrusive, because is still related to criminal
identification.
b. It can make mistakes with the dryness or dirty of the finger’s skin, as well
as with the age (is not appropriate with children, because the size of their
fingerprint changes quickly).