Patent ID: 7194137

Claim:
A method for processing a series of digital signals that each have an amplitude from the amplitude set consisting of a first subset of values and a second subset of values, the first subset of values including the most common amplitude and at least one other amplitude, the processing to reduce the amount of data used to represent the digital signals and to form codewords such that the more frequently occurring sequences of values of digital signals are represented by relatively short codewords and the less frequently occurring sequences of values of digital signals are represented by relatively long codewords, the method comprising, forming a codeword for each of a set of modes encountered in the series of digital signals, a distinct mode defined for each amplitude of the second subset of values; and for each encountered mode, forming a codeword for the events in the series of signals for the encountered mode, each event of each mode that is defined by an encountered amplitude of the second subset of values being the runlength of none or more signals having the most common amplitude followed by such encountered amplitude when all amplitudes other than the most common amplitudes and the encountered amplitude are considered as if they had the most common encountered amplitude, such that relatively short codewords are formed to represent modes that are relatively more likely to occur, and within any mode, relatively short codewords are formed to represent events that are relatively more likely to occur.