04464650 is referenced by 230 patents.

A compressor parses the input data stream into segments where each segment comprises a prefix and the next symbol in the data stream following the prefix. The prefix of a segment is the longest match with a previously parsed segment of the data stream. The compressor constructs a search tree data base to effect the parsing and to generate a pointer for each segment pointing to the previous segment matching the prefix. The search tree comprises internal nodes including a root and external nodes denoted as leaves. The nodes are interconnected by branches representative of symbols of the alphabet. Each parsed segment of the input data is represented by a path from the root to a leaf. The tree is adaptively constructed from the input data such that as each new segment is parsed, one new internal node of the tree is created from a leaf and new leaves are defined, one for each symbol already encountered by the encoder plus an additional branch to represent all potential but unseen symbols. The compressor transmits a leaf pointer signal for each parsed segment representative of the prefix thereof and the suffixed symbol of the alphabet. A decompressor constructs an identical search tree in response to the received leaf pointers so as to reconstitute the original data stream.

Title
Apparatus and method for compressing data signals and restoring the compressed data signals
Application Number
6/291870
Publication Number
4464650
Application Date
August 10, 1981
Publication Date
August 7, 1984
Inventor
Martin Cohn
Arlington
MA, US
Jacob Ziv
Haifa
IL
Abraham Lempel
Haifa
IL
Willard L Eastman
Lexington
MA, US
Agent
Albert B Cooper
Howard P Terry
Assignee
Sperry Corporation
NY, US
IPC
H03K 13/00
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