| 摘要 |
<p>PURPOSE:To improve encoding efficiency by scaling the amplitude of a two-dimensional spatial frequency component obtained by two-dimensional discrete cosine transformation by a prescribed scaler for respective basic blocks segmenting the picture element group of a transformed picture and adding, selecting and transforming the result. CONSTITUTION:The basic block of 8X8 picture elements segments the picture element group of the transformed picture by 4X4-number. They are two-dimensional discrete cosine-transformed for the respective basic blocks. A scaling circuit scales the amplitude of 8X8-number of the two-dimensional spatial frequency components obtained by the transformation and a scaling result for the picture element of the same position in the 4X4-number of basic blocks is added. One objective area is selected from the plural objective areas of two-dimensional discrete cosine transformation which are previously decided, based on the distribution of the component, in which an added result is zero in 8X8- number of added result. Picture element signals in the objective area are rounded into 8X8-number, and they are two-dimensional discrete cosine- transformed. Thus, encoding efficiency is improved.</p> |
