Browse Prior Art Database

Image Compression Optimizing Methodology

IP.com Disclosure Number: IPCOM000105714D
Original Publication Date: 1993-Sep-01
Included in the Prior Art Database: 2005-Mar-20
Document File: 2 page(s) / 38K

Publishing Venue

IBM

Related People

Duvall, KE: AUTHOR [+5]

Abstract

Image data represents a significantly different compression footprint relative to text or graphics information. Image data will expand in size when compressed by text-optimized algorithms. A 'footprint' is defined as the data representation in non-deterministic, characteristic fashion. That is, data which represents a certain type of information can be randomly sampled for its footprint to determine the optimal means of manipulating that data.

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Image Compression Optimizing Methodology

      Image data represents a significantly different compression
footprint relative to text or graphics information.  Image data will
expand in size when compressed by text-optimized algorithms.  A
'footprint' is defined as the data representation in
non-deterministic, characteristic fashion.  That is, data which
represents a certain type of information can be randomly sampled for
its footprint to determine the optimal means of manipulating that
data.

      A mechanism which predetermines the nature of data by applying
an initial buffer test algorithm which determines from pre and post
text and image compression applications whether the data
representation is an image format.

      In a UNIX* environment, on a client workstation, a selected
sample data pattern from the target data object is compressed with a
standard text compression algorithm.  If the compression results in
object expansion (the number of bytes increases), then an image
compression algorithm is applied.  If the object increases in size
again, the buffered test data pattern is discarded, and the data is
moved and stored without compression.

      This set of functions is based upon the notion that much of the
image data of interest in the Enterprise Storage Management System
(ESMS) environment is gray-scale or compressed TIFF.  Either of these
data formats will ALWAYS expand when applied to a Led-Zempel text
compression algorithm.

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