DRS \\ 7jun021

Operating Principles for Operating Principles for

Very small fingerprint Very small fingerprint

sensorssensors

Operating Principles for Operating Principles for

Very small fingerprint Very small fingerprint

sensorssensors

DRS \\ 7jun022

Progress in low-cost sensor systemsProgress in low-cost sensor systems

The first step is the movement from The first step is the movement from

Modular sensor devices Modular sensor devices silicon silicon

integrated sensor devicesintegrated sensor devices

– Cost is now driven by silicon sizeCost is now driven by silicon size

The second step is a new generation of The second step is a new generation of

very small devicesvery small devices

Small touch sensorsSmall touch sensors

Small slide sensorsSmall slide sensors

DRS \\ 7jun023

An example of a very small touch sensor

AuthenTec AES-3500 small touch sensor

Size of active sensing area

DRS \\ 7jun024

How do small touch sensors workHow do small touch sensors work

Acquiring enough repeatable information to match Acquiring enough repeatable information to match

accurately accurately

Use the higher density small-scale feature Use the higher density small-scale feature

information captured in high quality TruePrint images information captured in high quality TruePrint images

to perform matching using less skin areato perform matching using less skin area

Allowing flexible finger positioning on the sensorAllowing flexible finger positioning on the sensor

Use template compositing to store areas of finger Use template compositing to store areas of finger

skin larger than the sensor itselfskin larger than the sensor itself

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High Resolution High Resolution TruePrint ImagingTruePrint Imaging

AuthenTec’s very small touch sensors can capture highly detailed images with excellent repeatably.

This image is from an AES-3500 sensor running experimental high resolution control software.

DRS \\ 7jun026

High Resolution High Resolution TruePrint ImagingTruePrint Imaging

A topographic analysis program highlights some of the detail that can be extracted from the image.

DRS \\ 7jun027

Flexible finger positioning using a Flexible finger positioning using a composite template – concept illustrationcomposite template – concept illustration

Multiple touches during the enroll processMultiple touches during the enroll process Are logically interconnected Are logically interconnected Into a larger composite templateInto a larger composite template

Single touch images

Composite template

DRS \\ 7jun028

What information can be containedWhat information can be contained in a composite template? in a composite template?

Template is:Template is: Several views of a Several views of a

fingerfinger

Location of each Location of each view relative to view relative to othersothers

Image and/or Image and/or feature data for feature data for each vieweach view

Image representation

Pattern representation

Feature (minutia) data

Other data

•Relative location• Confidence

DRS \\ 7jun029

Verification using a composite templateVerification using a composite template

Conceptually:Conceptually: Compare live view against Compare live view against

each template vieweach template view Final score is statistical Final score is statistical

combination of all combination of all evaluationsevaluations

Template

• Relative Location• Match Score

Live imag

e

Match or Match or non-matchnon-match

Final score calculation

DRS \\ 7jun0210

How do small slide sensors workHow do small slide sensors work

Acquiring enough repeatable information to match Acquiring enough repeatable information to match

accurately accurately

Slide the finger across the sensorSlide the finger across the sensor

Capture a “stream” of small image slicesCapture a “stream” of small image slices

Allowing flexible finger positioning on the sensorAllowing flexible finger positioning on the sensor

Same sliding usage method allows flexible finger Same sliding usage method allows flexible finger

positioningpositioning

DRS \\ 7jun0211

Slide sensor operationSlide sensor operation

Template Match or non-match

Sensor

Small local processor

Slide sensors are required where lowest cost is paramount.

Inexpensive devices usually have small processors.

User slides the finger User slides the finger across the sensor across the sensor

User slides the finger User slides the finger across the sensor across the sensor

slide

Stream of image slices

DRS \\ 7jun0212

Slide sensor processing optionsSlide sensor processing optionsStream of

image slicesStitched image

segments

Sensor

Matching Options = Match raw

slices

Match stitched image

segments

|

Increasing processor load

Fin

ger

mov

emen

t

DRS \\ 7jun0213

Comparison of small sensorsComparison of small sensors

Sensor Sensor CostCost

Ease of Ease of use use

Typical Typical biometric biometric accuracyaccuracy

Front Front panel panel footprintfootprint

Interface Interface bandwidth bandwidth neededneeded

Small Small touch touch sensorsensor

Very lowVery low BestBest BestBest SmallSmall LowLow

Small Small slide slide sensorsensor

LowestLowest GoodGood GoodGood SmallestSmallest HighHigh

DRS \\ 7jun0214

For more information …For more information …

Back to Beginning

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commercial biometric systems

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Matching methods