| 摘要 |
PROBLEM TO BE SOLVED: To improve the quality of reproduced sound of a digital audio sigmal. SOLUTION: A minimal and maximal point detector 1 detects the local minimal point and the local maximal point in a waveform of an input digital audio sigmal, and a tilt calculation section 2 calculates a tilt value of a straight line for connecting adjoining the local minimal point and the local maximal point. A normalization value calculation section 3 calculates a value in which the value on the straight line for connecting the adjoining the local minimal point and the local maximal point, is subtracted from each sample value, as a normalization value. An auxiliary value calculation section 4 calculates the value in which the normalization value for each sample calculated in the normalization value calculation section 3, is added to the value in which a coefficient according to the sampling interval number between the adjacent local minimal point and the local maximal point is multiplied with the normalization value, as the auxiliary value. An output data creation section 6 adds the auxiliary value for each sample which is calculated in the auxiliary value calculation section 4 to the value on the straight line for connecting the adjoining the local minimal point and the local maximal point at timing of each sample, and outputs it. COPYRIGHT: (C)2008,JPO&INPIT
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