Programming

Front 1

Pre-processing steps for Iris

Back 1

- iris localisation
- iris normalisation
- image enhancement

Front 2

locating the Iris - first processing steps

Back 2

- first processing steps consists in locating the inner and outer boundaries of the iris

- In the Daugmans system integro-differential operators are used to detect the centre and diameter of the iris and the pupil.

Front 3

Locating the iris - grey-scale levels

Back 3

The iris image should have a minimum of:

- 70 grey-scale levels between the iris and the sclara

- 50 grey-scale levels separation between the iris and pupils for all eye colours

Front 4

Hamming distance

Back 4

Is the number of the same bits divided by the total number of bits.

e.g

20 bits - 10 differing bits (XOR)

10 / 20 = 0.50 (no match)

12 / 20 = 0.60

Front 5

False rejection rate (FFR)

Back 5

Security system failing to verify or identify an authorized person. (dirt on scanner can cause this etc)

is the measure of the likelihood that the biometric security system will incorrectly reject an access attempt by an authorized user.

FFR is typically stated as the ratio of number of false rejections divided by the number of identification attempts.

Front 6

False Acceptance rate (FAR)

Back 6

security system incorrectly verifying or identifying an unauthorized person.

FAR is the measure of likelihood that the biometric security system will incorrectly accept an access attempt by an unauthorized user.

A system FAR typically is stated as the ratio of the number of false acceptances divided by the number of identification attempts. n