| 摘要 |
<p>PURPOSE:To reduce the occurrence of block distortions which are produced when picture signals are converted into codes by means of a DCT circuit by allowing a filter controlling section to detect the time when a distortion occurs in a local decoded value and outputs a signal which control the title filter. CONSTITUTION:The output of a differential circuit 1 is supplied to a DCT circuit where transformation encoding is performed on the output after the output is divided into blocks and the output of the circuit 2 is supplied to a quantization circuit 3 for quantization. The quantization is performed at the circuit 3 in, for example, rough steps to a large differential in accordance with the visual characteristics of human beings. The output of the circuit 3 is divided into two parts and one part is supplied to a variable-length encoding circuit 4, with the other part being supplied to a reverse quantization circuit 7. The circuit 4 performs variable-length encoding on the inputted quantized data. Then the output of the circuit 4 is read out and sent to a transmission line at a fixed, transmission speed after the output is temporarily inputted to a buffer memory 5 and information data are accumulated.</p> |
