This document summarizes a study on exploiting the "Doddington Zoo" effect in biometric fusion. The Doddington Zoo refers to how some biometric subjects ("lambs" and "wolves") have higher false acceptance rates than others ("sheep"). The study shows that selectively fusing biometric data based on which subjects are lambs/wolves versus sheep can increase throughput with minimal cost. User-specific fusion of iris and fingerprint data from two datasets achieved equal error rates of 2% and 1.1%, lower than non-selective multibiometric fusion.

1. IEEE International Conference on Biometrics: Theory, Applications and Systems (BTAS) 2009
Exploiting the “Doddington Zoo”
Effect in Biometric Fusion
Arun Ross, Ajita Rattani and Massimo Tistarelli
arun.ross@mail.wvu.edu, ajita.rattani@diee.unica.it, tista@uniss.it

2. The “Doddington Zoo”
Lambs Wolves (high FAR)
Sheep
(well behaved)
Exploiting only complimentary Average Genuine Score
information in multi-biometric fusion may
result in increased throughput at minimal
cost

3. “Selective Fusion”

4. User- Specific Fusion (Iris)
FRatio Doddington Zoo

5. Cont…. (Finger)
FRatio Doddington Zoo

6. User Specific Selection of Modalities
Dataset Left Unit Right Unit Fusion EER (%)
Only (%) Only (%) (%) (User specific fusion)
(Multimodality)
Fingerprint 40.16 40.16 19.66 1.56
(WVU)
1.3
Iris 33.60 33.60 32.78 0.4
(CASIA)
0.3
Right Unit Left Unit CASIA (%) WVU (%)
Goats Goats 14.75 20.50
Lambs Lambs 1.64 1.25
Sheep Sheep 50 46.02
Goat Lamb 3.27 0
Goat Sheep 12.29 9.62
Sheep Lambs 1.63 7.11
Sheep Goat 13.93 7.94
Lamb Goat 1.64 1.67
Lamb Sheep 0.82 5.85
EER User Specific Selection: 2% 1.1 %
EER Multi biometric System 1.3 % 0.3 %