Abstract: An offset-difference coding process for data encoding and decoding wherein for each of the paired input data, the encoding process first determines the greater of the two input data, then calculates the difference between the two input data, replaces the larger input data with the calculated difference, and encodes the calculated difference and the smaller input data. The offset-difference coding process also generates an indicator if the larger input data that is replaced by the calculated difference is not statistically larger than the smaller input data.

Abstract: A data encoding and decoding system that comprises a composite fixed-variable-length coding process and an offset-difference coding process for improving data compression performance. A composite fixed-variable-length coding process encodes an input data by first comparing the input data to a predetermined threshold, then selecting a coding scheme from two preselected coding schemes and encoding the input data in accordance with the selected coding scheme. The composite fixed-variable-length coding process also generates an identifier to indicate the selected coding scheme to decode the coded output data if a response to comparing the input data with a predetermined threshold differs from a statistically determined response. An offset-difference coding process encodes a paired input data by first determining the greater of the two input data, then calculating the difference between the larger input data and the smaller input data and replacing the larger input data with the calculated difference.