| 摘要 |
PURPOSE:To shorten the time for quantization by classifying the representative vectors by a zero cross number to plural pieces of groups, determining the zero cross number of the input vector to be subjected to quantization and calculating distortions with the representative vector within the corresponding group. CONSTITUTION:The zero cross number n of the input vector is calculated and if this n is nj-1<n<nj, this input vector is determined as to have the shape approximate to the shape of the j-th representative vector. The distortion di of all the representative vectors belonging to this group is calculated. The representative vector of the number (i) at which the distortion di is smallest is determined. This vector is determined as the representative vector for the input vector X and the number (i) of the decided representative vector is made the quantization value of the input vector X. Since the number of the representa tive vectors to be subjected to the calculation of the distortions is limited in such a manner, the time for the calculation processing at the time of determin ing the definite representative vector is shortened. |
