| 摘要 |
PURPOSE:To suppress the generation of block distortion and to prevent the degradation of a picture by passing a forecast error signal through a space filter whose characteristic is changed for the unit of a frame, filtering the signal while changing the degree of filtering for the unit of the frame and afterwards, executing in-frame encoding processing. CONSTITUTION:For a dynamic picture signal inputted from a picture signal input terminal 1, a forecasting signal is subtracted by a forecasting signal subtracter 2 and a forecasting error is passed through a space filter 3. The degree of the filtering is changed with a fixed period for the unit of the frame. For example, the even-number frame forecasting error is filtered by turning ON and OFF for each frame and not defined as the forecasting error of the odd- number frame. Since only the high area components of both the time and space are deleted by this operation, the visual degradation is suppressed to be slight. The quantity of data to be generated can be controlled by changing the degree of filtering and the block-shaped distortion is eliminated as well. Further, by using this device also for controlling quantization, the control can be executed with the small degradation of picture quality over a wide range. |
