| 摘要 |
<p>PURPOSE:To improve the compression efficiency by dividing a conversion coefficient into plural categories according to the distribution of the dimension so as to apply different band grouping. CONSTITUTION:A 2-dimension cosine conversion (DCT) is applied at a DCT conversion section 2 to a one block picture signal 10 and the calculated is classified into four categories existing depending on where a large coefficient in a category analysis section 3 and a corresponding category number 12 is outputted. The DCT conversion coefficient 11 is split into plural bands according to the category number 12 in a band split section 5 to generate a vector 13 taking the conversion coefficient as the component included in each band is generated. A vector quantizing device 7 selects out a representative vector from the corresponding code book and outputs its number as a vector index 14. The category number 12 and the vector index 14 are coded by a coder 9 and a code 15 is outputted.</p> |
