| 摘要 |
<p>PURPOSE:To improve a compression ratio and to shorten a transmitting time while obtaining a high picture quality by coding a picture plane to be transmitted with the coding method different in quantizing characteristic for plural areas each. CONSTITUTION:A picture plane is classified into plural area parts and quantized with the quantizing characteristics in accordance with the picture quality required for respective classified are parts. For example, a central area 3 is cut from a whole picture plane 1, fine quantization is executed to the cut central part, and an area identifying signal is added to the transmitting signal. On the other hand, coarse quantization is executed to a peripheral area outside the central area 3, and as a whole, a high picture quality and a compressed ratio are obtained. Consequently, at the time of decoding, the quantizing characteristics may be changed over according to the fact what area a picture element to be decoded by the area identifying signal belongs to the surface of the picture plane, and thus, the decoding is executed without trouble.</p> |
