Investigation of Optical Compression Techniques for Dither Coding

Abstract

The purpose of this study was to perform a computer simulation study in which several dither coding techniques were evaluated in order to determine their relative performances in terms of compression and output image quality in reproducing gray scale imagery transmitted over facsimile channels. Gray scale images can be represented in two ways. One method produces gray scale using multilevel pixels (i.e. each pixel can have one of 2 gray level values, where n is the number of bits of resolution of the gray scale employed). The second method simulates gray scale by locally adjusting the ratio of black pels to white pels (dithering), using spatial frequency to give the appearance of gray scale. Although the multilevel approach produces higher quality images, the dithering approach is more compatible with existing facsimile equipments. Dither algorithms; Facsimile transmission; Gray scale images; Telecommunication systems; Data compression; Adaptive clumped dithering; Clump plane separation; Adaptive ordered dithering.

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Document Details

Document Type
Technical Report
Publication Date
Apr 01, 1988
Accession Number
ADA206140

Entities

Organizations

  • Delta Information Systems (United States)

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Aerial Photographs
  • Algorithms
  • Boundaries
  • Coding
  • Computer Programming
  • Computer Simulations
  • Data Compression
  • Decoding
  • Differential Pulse Code Modulation
  • Facsimile Equipment
  • Gray Scale
  • Image Compression
  • Images
  • Information Systems
  • Pulse Code Modulation
  • Simulations
  • Standards

Readers

  • Computer Networking
  • Computer Vision.
  • Image Processing and Computer Vision.