Patent ID: 7071853

Claim:
A method of compressing data, wherein said data is in the form of discrete units, by determining an overall code specific to the units, comprising the steps of: a) grouping the units in terms of a common behavior pattern; b) for each said group of units, assigning a group specific code, the sizes of said group code being ordered according to the probability of the unit occurring; c) assigning a unit identifier code which is specific to identify an individual character within the group, the overall code comprising the concatenated group specific and identifier codes; characterized wherein, step c), the identifier code is of the minimum size to allow for each unit which could occur in that group to be assigned specifically; said discrete units are is divided into a number of sub-units; at least one sub-unit is treated and compressed; and the overall compressed code comprises a concatenation of any compressed sub-unit codes and any uncompressed sub-units themselves.