| 摘要 |
PURPOSE:To prevent the increase of the transmission data volume regardlees of adoption of the hierarchical expression, to reduce the scale of hardware, and to decode a signal at a high speed. CONSTITUTION:A first hierarchy is constituted by an input digital picture signal. An average value m1 of 2X2=4 picture elements ((a), (b), (c), and (d)) in the first hierarchy is formed. A second hierarchy consists of the average value formed in this manner. Transmission of one picture element (d) out of four picture elements is omitted. Consequently, average value data and three picture elements are transmitted, and the transmission data volume is equal to the data volume of original picture elements. An average value M1 is formed from 2X2 data in the second hierarchy. Average values M1 to M4 constitute a third hierarchy. An average value M of M1 to M4 is formed. A fourth hierarchy consists of the average value M. Not average values but difference data to average values of higher-order hierarchies except the highest hierarchy may be transmitted. |
