Patent attributes
A method of compression is disclosed in which an input sequence of bits is divided into a plurality of portions. Each portion is sub-divided into a plurality of sub-divisions. Frequency analysis is performed to determine the number of occurrences of each sub-division permutation and a processed sequence of bits is generated based on the frequency analysis. The processed sequence of bits includes extraction information for use in reconstructing said input sequence of bits from said processed sequence of bits. The extraction information comprises sub-division order information identifying an ordered sequence comprising each possible sub-division permutation arranged in order of how many times, within said input sequence of bits, a portion comprises a sub-division having bits arranged in that possible sub-division permutation. The sub-division order information includes an index value representing the order of the corresponding ordered sequence, based on a preconfigured mapping between said index value and the order of the corresponding ordered sequence.