Huffman coding

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Huffman coding

(algorithm)
A data compression technique which varies the length of the encoded symbol in proportion to its information content, that is the more often a symbol or token is used, the shorter the binary string used to represent it in the compressed stream. Huffman codes can be properly decoded because they obey the prefix property, which means that no code can be a prefix of another code, and so the complete set of codes can be represented as a binary tree, known as a Huffman tree. Huffman coding was first described in a seminal paper by D.A. Huffman in 1952.

Huffman coding

A statistical compression method that converts characters into variable length bit strings. Most-frequently occurring characters are converted to shortest bit strings; least frequent, the longest. Compression takes two passes. The first pass analyzes a block of data and creates a tree model based on its contents. The second pass compresses the data via the model. Decompression decodes the variable length strings via the tree. See LZW.
References in periodicals archive ?
Key words and phrases : Sampling, Sparsity, Compressed Sampling, Huffman codes
The new approach we present is also information theoretic and uses tools from the theory of Huffman codes to develop a deterministic construction of a sequence of binary sampling vectors [a.
This should not be a surprise since the algorithm was inspired by the theory of Huffman codes.
It is optimal because the sampling scheme can be associated exactly with the Huffman codes and we have that [q.
We now turn our attention to fixed-to-variable length codes, in particular Shannon and Huffman codes.
Keywords: Source coding, prefix codes, Kraft's inequality, Shannon lower bound, data compression, Huffman code, Tunstall code, Khodak code, redundancy, distribution modulo 1, Mellin transform, complex asymptotics.
While Huffman has already known that the average code length is asymptotically equal to the entropy of the source, the asymptotic performance of the Huffman code is still not fully understood.
Recall that Huffman code is a recursive algorithm built over the associated Huffman tree, in which the two nodes with lowest probabilities are combined into a new node whose probability is the sum of the probabilities of its two children.
He describes in detail cryptographic protocols, key management, message authentication, applications such as email and Internet security, new wrinkles in noncryptographic security issues such as hacking and cybercrime, and closes with very useful descriptions of information theory and coding including Huffman codes.
If we extend now the words table to contain more than 30 words so the compression rate will be grater but in contrast the Huffman code will be larger.
Once the Huffman code table of each letters is generated, we compress each verse by writing the code of its characters in the compressed file.
Arabic Text Compression Using Huffman Code, The Arabian Journal for Science and Engineering, 16 (4B).