Use of Spatial Filtering to Match Wide Dynamic Range Grayscale Imagery to a Lower Resolution Display,

Abstract

We investigate the ability of nonlinear spatial filtering to reduce the amount of information that is lost when a display device has a lower dynamic range than the grayscale imagery to be displayed on it. Dynamic range compression can be achieved by attenuating an assumed low-frequency multiplicative background and enhancing higher frequencies using homomorphic filtering. This technique, originally described by Oppenheim for images formed by reflection of visible light, is extended to images formed by emission of IR radiation and transmission of X-ray and gamma-ray radiation. Examples are given which show dynamic range compression of the three types of images achieved by means of a homomorphic filtering and display procedure having no free parameters which must be optimized to suit the particular input image. (Author)

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Document Details

Document Type
Technical Report
Publication Date
Jan 01, 1977
Accession Number
ADA037846

Entities

People

  • J. F. Boulter

Tags

Communities of Interest

  • Counter IED
  • Energy and Power Technologies
  • Materials and Manufacturing Processes
  • Sensors
  • Weapons Technologies

DTIC Thesaurus Topics

  • Brightness
  • Detectors
  • Difference Frequency
  • Distortion
  • Dynamic Range
  • Explosive Charges
  • Filters
  • Filtration
  • Frequency
  • Linear Filtering
  • Photographs
  • Power Spectra
  • Radiation
  • Sine Waves
  • Spatial Filtering
  • Spectra
  • Visible Spectra

Fields of Study

  • Physics

Readers

  • Adaptive Control and Estimation with Uncertainty in Dynamic Systems.
  • Medical Imaging.
  • Radar Systems Engineering.