| 摘要 |
PURPOSE:To prevent vector quantized errors from accumulation by inserting an LPF into an output of frame memory and vector-quantizing a block of a picture signal channel instead of that of a predicted error signal when the corelation between continuous pictures becomes extremely small. CONSTITUTION:A digitized picture signal channel 1 is the sample which is given in the order of the raster scanning direction. The signal channel 1 is sent to a raster/block convertor circuit 2, partitioned into several blocks, and scanned and converted into blocks in the order in which these block are units. Assuming that a picture signal channel 3 which is made into blocks in the fth frame, and a prediction signal channel 44 are channels Sf and Pf, respectively the channel Pf is a signal obtained by removing a high and from the channel 3 of a signal source vector and a reproducing signal of the block in the same position as that of previous one-frame period. Since vector-quantized errors appear in a high band such as granular noises, low-pass filter LPF43 prevents these quantized errors from accumulation; therefore pictures having high quality can be obtained without fail. |
