One of file compressed type. With the type which with the free software “LHA” which glory Yasusi Yosizaki developed is used, it has spread mainly in the country. As the compressed type for Windows, it is the type which is utilized widely along with Zip type. Specification being open, the various corresponding tools are open, in addition, also the corresponding software for UNIX affiliation OS and Mac OS is developed. Making compressed type in order to do software distribution from the fact that to bulk compressibility it is superior, via network it is well utilized.

LZW <LZW algorithm>

Reading: [eruzetsutodaburiyu]
Full spelling: Lempel Ziv Welch
Field:
Expression of information > data compression > LZW

In 1984 the Sperry corporation (the present Unisys corporation) the data compression algorithm which Terry Welch announces. In 1977 the system Welch improving the technique, dictionary compression which it announces Abraham Lempel and Jacob Ziv as “LZ77” algorithm.

Dictionary compression, the occasion where a certain data is compressed, the longest agreement character string is searched from midst of the data which is already read, it is the method of replacing at the position and agreement length if (you can discover).

Welch devised construction of the dictionary and management method, developed the algorithm which it keeps encoding efficiently, Lempel, added his own name to the Ziv both person you named “LZW”.

The Sperry corporation registered LZW with worldwide each country as patent. The same company combining with the Burroughs corporation, becomes the Unisys corporation in 1986, presently the same company possesses right.

LZW algorithm <LZW>

Field:
Expression of information > data compression > LZW algorithm

In 1984 the Sperry corporation (the present Unisys corporation) the data compression algorithm which Terry Welch announces. In 1977 the system Welch improving the technique, dictionary compression which it announces Abraham Lempel and Jacob Ziv as “LZ77” algorithm.

Dictionary compression, the occasion where a certain data is compressed, the longest agreement character string is searched from midst of the data which is already read, it is the method of replacing at the position and agreement length if (you can discover).

Welch devised construction of the dictionary and management method, developed the algorithm which it keeps encoding efficiently, Lempel, added his own name to the Ziv both person you named “LZW”.

The Sperry corporation registered LZW with worldwide each country as patent. The same company combining with the Burroughs corporation, becomes the Unisys corporation in 1986, presently the same company possesses right.

LZW patent <GIF patent>

Reading: [eruzetsutodaburiyu] and [tsu] sewer
Alias:
Unisys LZW patent
Field:
Expression of information > data compression > LZW patent
Multimedia > graphics > picture type > LZW patent

The patent regarding the LZW compressed method which the Unisys corporation possessed, is utilized with the GIF picture format and the like. Presently already it has lapsed.

In the patent which it applies the Sperry corporation of that time “High speed data compression and decompression apparatus and method” (high-speed data compression and thawing) (USP4,558,302) as in 1983 June, it was formed in 1985 June. With the system Terry Welch improving the technique, dictionary compression which it announces Abraham Lempel and Jacob Ziv as “LZ77” algorithm, taking the initial 3 in 1977, it is called alias “LZW”. In Japan “digital signal stream compressed method and compressed device” (public notice number: Flat 5-68893) It is applied in 1984 June as, acquires similar patent even with other worldwide each country. The same company combining with the Burroughs corporation in 1986, became the Unisys corporation, also this patent was taken over to the Unisys corporation.