System und Verfahren zur pre-entropischen Codierung

摘要

According to the invention, the elementary stage of pre-entropic coding consists in calculating from a first data source a second data source in which a group of two or more characters from the first data source is represented by a new character, and in calculating for this second data source the product of the entropy and new number of characters. Thereafter, for a further data source with a further group of two or more grouped characters from the first data source is calculated a further product of the entropy and new number of characters. The group of characters from the first data source to which is assigned the lower product of entropy and number of characters is stored and replaced by the new combination character, following an iteration covering additional data sources. After the replacement, a compressed data source is located in the destination file. The elementary cycle is reapplied to this modified data source until the coding gain resulting from replacement is compensated for by the increase in notation in a header file in which the replacement stages are recorded. Decompression on the basis of this header file is extremely rapid and requires almost no memory space.