| 摘要 |
PURPOSE:To realize the coding with an excellent compression efficiency by obtaining an optimum coefficient scanning method with respect to given transformation. CONSTITUTION:A duplicate block transformation section 11 applies duplicate block transformation to an input picture and a quantization section 12 quantizes a transformation coefficient. A priority decision section 13 decides the priority of each coefficient based on statistic of a quantization index of the transformation coefficient, a coefficient scanning order decision section 14 uses the priority decided by the priority decision section 13 to decide the sequence of coefficient scanning. A transformation coefficient scanning section 15 scans linearly the transformation coefficient in the order decided by the coefficient scanning order decision section 14 and a variable length coding section 16 applies quadratic run length coding to the transformation coefficient subject to linear scanning. Thus, the statistic distribution of the transformation coefficient is used to decide the sequence of scanning of the transformation coefficients, then coding to obtain a visually excellent decoding picture is realized with less code quantity. |
