Data compression apparatus, data expansion apparatus, data compression program, data expansion program, data compression method, and data expansion method

摘要

A data compression apparatus (10) predicts, using an external value e[i - m] at a position shifted by a position difference m from an external value e[i] at a target position i in an external data string e, a predicted value p[i] of an input value d[i] at the target position i in an input data string d. The data compression apparatus (10) calculates, as a residual r[i], the difference from the predicted value p[i] that has been predicted. The data compression apparatus (10) then codes the calculated residual r[i], and generates a code c[i] relating to the input value d[i].