The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.

The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.

Date of Patent:
Jun. 16, 1992

Filed:

Jul. 12, 1991
Applicant:
Inventor:

Thomas B Pritchard, Vancouver, WA (US);

Assignee:

Hewlett-Packard Company, Palo Alto, CA (US);

Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G06K / ; G06K / ; H04N / ;
U.S. Cl.
CPC ...
382 56 ; 3582611 ;
Abstract

The invented data compression/decompression methods, device, and resulting data structures, operate by noting likenesses and differences between portions of data, and effecting data storage only with respect to the noted differences. The compression method arranges the data, compares portions of the data, and provides a flag to signal changes between adjacent data portions. The decompression method reads a portion of data, identifies whether the flag signals any changes in the data, and if so, reads a subsequent portion of data; but if no changes are signaled, then the first portion of data is duplicated. The invented device includes memory, a structure for storing data in the memory, data stored in the memory with flags to signal changes in the data, and structure for accessing and using the stored data. The invented data structure includes data divided into predetermined sections, and flags associated with the sections to signal changes within the sections.


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