JPEG: Entropy Coding
(Huffman Coding)

Data, which result from the preceding steps, are provided with a different quantity of redundancy, which does not supply any contribution for the quality of the image representation. This redundancy is reduced e.g. with the help of a Huffman coding.

The basis for this coding is a code tree according to Huffman, which assigns short code words to symbols frequently used and long code words to symbols rarely used.

Beside Huffman coding another procedure is specified, which does not have a practical meaning because of the patent situation (arithmetic coding).

Additionally a special form of Run Length Encoding is applied.