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Biometric template selection and update: a case study in fingerprints

Source:Pattern Recognition, Vol. 37, 2004, pp.1533-1542Authors: Umut Uludag, Arun Ross and Anil JainSpeaker: Shu-Fen Chiou(邱淑芬 )Date: 2004/11/04

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Outline

IntroductionProposed methodExperimental resultsConclusionsComment

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Introduction

A typical biometric system operates in two distinct stages: Enrollment stage. Authentication stage.

In order to account for variations in the biometric data of a user, multiple templates corresponding to each user may be stored.

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Problem

partial overlap

different sensors

a period of 6 weeks exhibiting difference in moisture content

Result in inferior performance

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Solve problems

Store multiple templates Consider: number of templates storage computational

Efficient function: automatic select templates

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Proposed method

Template selection DEND MDIST

Template update BATCH-UPDATE AUGMENT-UPDATE

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Template selection

N fingerprint

images

Select K templates

(K<N)

Store templates in

database

Selection:

•Random selection

•Systematic selection Better performance

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Template selection

DEND

200250220260

200150160210

250150170175

22016017050

26021017550

M

1

2

3

4

5

1 2 3 4 5

5 ,2 NK

1 2 3 4 5

50

150

200

100

4 ,1T

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Template selection

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Template selection

MDIST

232.5

180

186.25

150

75.173

200250220260

200150160210

250150170175

22016017050

26021017550

M

1

2

3

4

5

1 2 3 4 5 Avg.5 ,2 NK

2 ,1T

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Template Update

BATCH-UPDATE: newly acquired data.AUGMENT-UPDATE: after augmenting the new data set with current template set.

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Experimental resultsDEND selection

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Experimental resultsMDIST selection

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Experimental results

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Experimental results

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Conclusion

A systematic template selection procedure results in better performance than random template selection.

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Comments

利用 DEND的方法分完群後 , 計算群裡面的 template數量大小，加上權重的觀念 , 加快比對的效率。經過一段時間測試，以權重而分的 template被找到的次數再調整 template的權重。

(a) weight=3

(b) weight=4

(c) weight=2

(d) weight=1

(e) weight=1

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Comments

動態決定群的數量