| 摘要 |
<p>PURPOSE:To improve the efficiency of the coefficient coding of orthogonal transformation by coding two-dimensional vector information instead of distance information on a one-dimensional space when a distance on a two-dimensional space is smaller than that on the one-dimensional space. CONSTITUTION:The boundary of areas where significant coefficients are distributed are coded. Namely, the significant coefficients are coded by one-dimensional scan such as zigzag scan, and vectors which jump along the boundary when they reach the areas of the significant coefficients are coded. Since the directions and sizes of jumps concentrate on the two ways of 'one on the right' and 'one on the left' in zigzag scan, coding is attained with the code quantity of less designation in distribution range of the significant coefficients by allotting short code words on two vectors. Since the jump vectors of short code length are used instead of a runlength which requires a comparatively long code length, high efficiency can be obtained.</p> |
