| 摘要 |
<p>PURPOSE:To decrease the reduction in the information quantity attended with the deterioration of picture quality at coding by selecting a demodulation axis of a chrominance signal of each picture so that the sum of quantization bit numbers of two chrominance signals is decreased. CONSTITUTION:A color burst 62 of a chrominance signal input 61 is inputted to a color burst input 62-1 of color demodulation blocks 31-38 and a color burst 63 whose phase is shifted by +11.25 deg. is outputted. A phase shift color burst output is fed to the block 32 similarly, the signal 63 is fed to a color demodulation block of the next stage as a color burst input 62. First and 2nd demodulation outputs 64, 65 of the blocks 31-38 are respectively inputted to 1st and 2nd demodulation output selection circuits 41, 42 and one of eight signals is selected. The signal selected to reduce a quantization bit number of the two chrominance signals is converted into a digital signal by A/D converters 46, 47, inputted to a coder 70, in which the signal is processed.</p> |
