| 摘要 |
PURPOSE:To attain suitable coding both for still and dynamic pictures by allowing to switch automatically space resolution and time resolution depending on an input signal. CONSTITUTION:The coding circuit is provided with a difference circuit SUB1 outputting the difference between a present picture signal and a forecast picture signal before n-field, a difference circuit SUB2 outputting difference between its output and a signal before m-bit, a quantizing circuit Q, a transmission buffer Buf, and a local coding circuit. A pre-processing circuit discriminates whether an input picture signal is a still picture or a dynamic picture. A control circuit controls switches SW1, SW2 by the output of the pre-processing circuit and in case of a still picture, they are connected in solid lines and in case of a dynamic picture, they are connected in dotted lines. That is, in case of the still picture, the output of a memory FM2 at the final stage of a local decoding circuit is inputted to the difference circuit SUB1. In case of the dynamic picture, the two difference circuits are disconnected by a signal from a transmission buffer Buf and the coding is stopped. |
