Optical Enhancement of Degraded Fingerprints.

Abstract

The similarities and differences between fingerprints enable degraded fingerprints to be optically enhanced for the purpose of identification. A coherent optical processing system was used to locate and analyze the spectra of features that uniquely identify fingerprints. The spectra of these ridges and ridge characteristics (minutiae) are located in harmonic bands of spatial frequencies for all types of fingerprints. A general set of simple filters was developed to enhance the identifying features of degraded fingerprints. Simple binary filters (lowpass, bandpass, highpass, and contrast reversal) use the circular symmetry of fingerprint spectra to enhance the degraded fingerprints. Schlieren and Laplacian filters perform an edge enhancement on the fingerprint ridges. These techniques improved the identifiability of degraded fingerprints while maintaining the generality of the procedure and the integrity of the fingerprints. (Author)

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Document Details

Document Type
Technical Report
Publication Date
May 01, 1986
Accession Number
ADA170459

Entities

People

  • Hal E. Olimb

Organizations

  • Air Force Institute of Technology

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Bandpass Filters
  • Biometric Security
  • Digital Computers
  • Digital Image Processing
  • Digital Images
  • Filtration
  • Fourier Transformation
  • Frequency Bands
  • Frequency Domain
  • Identification Systems
  • Image Processing
  • Optical Images
  • Optical Processing
  • Optical Properties
  • Power Spectra
  • Security
  • Two Dimensional

Readers

  • Computer Vision.
  • Image Processing and Computer Vision.