Accession Number:

ADA037846

Title:

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

Descriptive Note:

Corporate Author:

DEFENCE RESEARCH ESTABLISHMENT VALCARTIER (QUEBEC)

Personal Author(s):

Report Date:

1977-01-01

Pagination or Media Count:

51.0

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

Subject Categories:

  • Optics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE