| 摘要 |
<p>PURPOSE:To obtain a mean value at a reception side when the difference of digital video signals is encoded and to improve efficiency by keeping symmetric ranges in upper and lower sides centering the mean value. CONSTITUTION:The mean value (y) at every sub block is formed at a mean value forming circuit 3, and the difference + or - between the mean value and the level of each picture element is detected at a subtraction circuit 10. The distribution of the level of the picture element is checked at every sub block at a distribution detection circuit 13, and an additional information generation circuit 12 generates additional data corresponding to the distribution. The additional data consists of the information of the difference and a code of two bits of each picture element, and the two bits show values 0, -1, +1, or -2. The value 0 corresponds to the mean value (y), +1 to (y+ ), -1 to (y-1), and -2 to another level. Encoded mean value information, the information of the difference , and the code of two bits of each picture element are transmitted.</p> |
