| 摘要 |
<p>PURPOSE:To suppress the degradation of the picture quality to make a high- efficiency transmission possible, by outputting an intraframe forecaseted error to decode a picture signal, only when the absolute value of an interframe forecasted error is a certain value or above, in case that the quantity of contents of an output bufer memory exceeds a certain value. CONSTITUTION:The picture signal of the input terminal 1 is fed to a subtractor 3 through an A/D converter 2. The difference between the picture signal and a local decoding signal from a frame memory 7 is operated by the subtractor 3, and a output signal (c) is fed to a limiter 4. In case that the quantity of contents of a buffer memory 9 is certain value THL or above, the circuit 4 outputs a signal (d) only when the absolute value of the signal (c) is a fixed value LIM or above; but in case that the quantity of contents of the buffer memory 9 is lower than the value THL, the circuit 4 outputs the signal (c) as it is. The output signal is encoded by an intraframe encoder 5, and is inputted to an address encoder 8 and an adder 6. The adder 6 supplies the local decoding signal to the memory 7, and the encoder 8 encodes the signal and supplies the output signal to the memory 9, and the signal is tansmitted to a transmission line from an encoded output terminal 10. Thus, a high-efficiency transmission having the picture quality suppressed the degradation is possible.</p> |
