Karl Jones: Created page with "In coding theory, a '''variable-length code''' is a code which maps source symbols to a variable number of bits. == Description == Variable-length codes can allow so..."

2016-09-20T17:36:17Z

Created page with "In coding theory, a '''variable-length code''' is a code which maps source symbols to a variable number of bits. == Description == Variable-length codes can allow so..."

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In [[coding theory]], a '''variable-length code''' is a [[code]] which maps source symbols to a variable number of bits.

== Description ==

Variable-length codes can allow sources to be [[Data compression|compressed]] and decompressed with zero error (lossless data compression) and still be read back symbol by symbol.

With the right coding strategy an [[Independent and identically distributed random variables|independent and identically-distributed source]] may be compressed almost arbitrarily close to its [[Entropy (information theory)|entropy]].

This is in contrast to fixed length coding methods, for which data compression is only possible for large blocks of data, and any compression beyond the logarithm of the total number of possibilities comes with a finite (though perhaps arbitrarily small) probability of failure.

Some examples of well-known variable-length coding strategies are [[Huffman coding]], [[Lempel–Ziv coding]], and [[arithmetic coding]].

== See also ==

* [[Code]]
* [[Coding theory]]
* [[Entropy (information theory)]]
* [[Independent and identically distributed random variables]]

== External links ==

* [https://en.wikipedia.org/wiki/Variable-length_code Variable-length code] @ Wikipedia

[[Category:Computing]]

Variable-length code - Revision history

Karl Jones: Created page with "In coding theory, a '''variable-length code''' is a code which maps source symbols to a variable number of bits. == Description == Variable-length codes can allow so..."