| 摘要 |
<p>PURPOSE:To reduce the occurrence of distortion in a reproduced picture by setting a prediction coefficient to a larger value when the state of a transmission line is excellent and decreasing the prediction coefficient to a smaller value when the state of the transmission line is bad so as to reduce the compression efficiency somewhat. CONSTITUTION:An extrapolation prediction means 9 uses a prediction coefficient selected by a prediction coefficient selection means 10 to obtain a prediction picture signal string from a reproduced picture. The selection of a prediction coefficient depends on the state of the transmission line, and when a transmission state detection means 11 expects it that the detected state of the transmission line is wrong and the occurrence of a transmission error is possible, the prediction coefficient is selected to be 3/8, and in other case, the prediction coefficient is selected to be 1/2. Since the prediction coefficient is selected large when the state of the transmission line is excellent, the coding efficiency is excellent and when the state of the transmission line is deteriorated and a transmission error takes place, the prediction coefficient is selected to be small to increase the redundancy and the effect of distortion is restricted to a near distance thereby reducing the production of the distortion in the reproduced picture at the receiver side.</p> |
