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Signal and Image Processing in Biometric System Applications

Dr. R. KalpanaDean, Dpt. Of Biomedical

EngineeringRajalakshmi Engineering College

Chennai

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Introduction Importance and significance Different Biometrics Different processing techniques Matching and Decision Governing bodies Limitatons and Future scope

Topics

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Introduction It is an authentication system – replaces existing systems

like pins, signature etc.

Introduction cntd…

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Importance and Significance More secured, cannot be stolen and changed Unique, time invariant, acceptable, available Systems has vendor specific algorithms and

hence proprietoryship Much useful in public benefit schemes Can be used in logical and physical networks Enrollment and presentation – two stages of

operation Template features

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Biometric parameters

Voice Infrared facial

thermography Fingerprints Face, Iris, Ear EKG, EEG Odor, Giat keystroke dynamics, DNA Signature,Retinal scan Hand & finger geometry Subcutaneous blood

vessel imaging

Various sensors

Ultra sound, thermal, capacitive – fingerprints

Camera, Mic, light source

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Accuracy False match rate False nonmatch rate Failure to enrollment rate\ No single metric indicates how well a biometric system or

device performs: Analysis of all three metrics is necessary to assess the performance of a specific technology.

Fingerprints

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1. Preprocessing2. Gabour filters3. Enhancement, Binarisation and

thinning4. Feature extraction5. Template creation6. Final presentation and comparision

Minutiae detection and post processing

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Two main post-processing types:

Structural post-processing Minutiae filtering in the gray-scale domain

Iris recognition

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Sensing – To approachesDaugmann and Wildes et al.,Light sourceLocalisationRepresentation

Typical example

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Iris localisation

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Daugmann approach Gradient ascent algorithm

Wildes et al., uses histogram based and Hough transform

Matching – Iris and System performance Correspondance

Shift, scaling, rotation, pupil dilation Match goodness

Hamming distance – DaugmannNormalisation correlation – Wields

Decision Bionomial distribution Fisher’s linear discriminant function System Performance Performed by IriScan or Iridian They generate FMR and FRR score

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