| 摘要 |
<p>PURPOSE:To fix data of a variable length code to a prescribed length and to obtain an accurate decoding result at the time of special reproduction without deteriorating picture quality on a decoding-side by assuming more than two quantization levels from data of a luminance signal before orthogonal conversion, predicting code quantity and code quantity, for example. CONSTITUTION:An inputted composite color video signal is converted into a digital signal by an AD converter 1, and it is supplied to a luminance/ chrominance signal separation circuit 5. A chrominance signal which is divided in the circuit 5 is demodulated into an U-component and a V-component along two demodulation axes of colors, and they are time base-multiplexed so as to be written into a memory 7 with the luminance signal, for example. Data is divided into small areas of eight picture elements x eight picture elements on a screen from the memory 7 and they are read. More than two quantization levels are assumed by data of only luminance and code quantity is predicted. Then, data is discrete-cosine-converted by DCT 8. Then, it is quantized by a quantization table computing element 9.</p> |
