| 摘要 |
<p>PURPOSE:To attain a highly efficient encoding without the deterioration of picture quality by appropriately switching a mean and variance calculated from an input block and an estimated mean and variance from the old block which has been encoded. CONSTITUTION:Video data inputted from a video data input terminal 1 subtracts the estimated value of the inter-output frame of a frame memory 16 in a subtractor circuit 2. In terms of the estimated error signal, a mean separator circuit 3 subtracts the mean at every block, and a normalization circuit 4 calculates the variance at every block. After the signal is normalized with the aid of the variance, it is vector-quantized by a vector quantization encoding circuit 5 based on the prescribed characteristic. Index information being the quantized output is supplied to a decoding circuit 10, and simultaneously it is multiplexed in terms of time division with the output of a variance information generator circuit 12 and that of a mean information generator circuit 14 in a multiplex circuit 6. A code pattern is assigned to the output of the circuit 6, and its speed is smoothed. After the output is converted in a code format applicable to a transmission line, it is transmitted to an output terminal 9.</p> |
