Fingerprint Recognition Through Circular Sampling

1 / 26

# Fingerprint Recognition Through Circular Sampling - PowerPoint PPT Presentation

Fingerprint Recognition Through Circular Sampling. David Chang* and Joseph Hornak Rochester Institute of Technology Rochester, NY 14623-5604. Introduction. Useful for personal identification. Valuable to criminal investigators and forensic scientists. Overview. Introduction Background

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.

## Fingerprint Recognition Through Circular Sampling

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

### Fingerprint Recognition Through Circular Sampling

David Chang* and Joseph Hornak

Rochester Institute of Technology

Rochester, NY 14623-5604

Introduction
• Useful for personal identification.
• Valuable to criminal investigators and forensic scientists.
Overview
• Introduction
• Background
• Theory
• Methods
• Results
• Conclusion
• Future Work
Background
• Fingerprint Uniqueness
• Obstacles
• AFIS Method
Fingerprint Uniqueness
• Major: Central pattern
• arch, loop, whorl
Fingerprint Uniqueness
• Minor: Minutiae
• ridge termination, bifurcation
Obstacles
• Rotation
• Displacement
• Missing area
• Image defects
AFIS Method
• Image enhancement
• Feature extraction
• Feature mapping
• Classification via flow maps
• Matching
• # of minutiae
• Euclidean distances
Theory: Sampling Process

Fingerprint Image

Concentric Circle Sample

A = 8

A = 16

MArea Ratio = 0.5

Match Metric: Area Ratio
• Average of ratio between the areas of corresponding circles in the two samples being matched.

A = 8

A = 16

MAX = 6

MCorrelation Fraction = 0.75

Match Metric: Correlation Fraction
• Average of the max value in the correlated signal divided by smaller area of corresponding circles in the two samples being matched.

Low Match Probability

High Match Probability

Match Metric: Angular Density
• Determine mean square error (MSE) among angles corresponding to highest magnitude in the correlation signal.

MAngular Density = 1 - 2(MSE)/

Methods
• Source Images
• 48 Synthetic Fingerprint Images
• 512 x 512 pixels at 1-bit/pixel
• Match Matrices
• 48 x 48 matrix where each column sample is matched against each row source sample.
• Done for the 3 metrics.
• Observe effects
• Missing Areas
• Rotation
• Examine displacement effects

Area Ratio

Correlation Fraction

Angular Density

Results: Unchanged Variables

Area Ratio

Correlation Fraction

Angular Density

Results: Arbitrary Area Removed

Area Ratio

Correlation Fraction

Angular Density

Results: Rotation Effects

Column images rotated 45

MArea Ratio

MCorrelation Fraction

MAngular Density

Arch

16

0

-16

16

0

-16

16

0

-16

-16 0 16

-16 0 16

-16 0 16

Loop

16

0

-16

16

0

-16

16

0

-16

-16 0 16

-16 0 16

-16 0 16

Whorl

16

0

-16

16

0

-16

16

0

-16

-16 0 16

-16 0 16

-16 0 16

Results: Displacement Effects
Conclusion
• Of the three metrics, the angular density metric proves to be most effective.
• Displacement effects show that a consistent selection of the circles center is necessary.
Future Work
• Image enhancement
• Test on actual fingerprints
• Observe effects of less circles
• Test on larger database
• Code optimization

### Thanks!

Fingerprint Chicks
• Materials:
• Yellow
• Tempera paint
• Wash tubs
• Large construction paper
• Glue
• Directions:
• 1.Each student chooses a construction paper for background.
• 2.Have students come up one at a time, to gently dip their hands and fingers in the yellow tempera paint.
• 3.Each will place their hands and fingers on their paper, making a fingerprint.
• 4.Kids decorate their fingerprints to look like a new Spring chick.