| 摘要 |
PURPOSE:To obtain the service of plural picture quality classes in a same transmission picture by partially encipyerment-processing frequency component data after orthogonally converted in a picture encoder, transmitting it to a transmission line and controlling the quality of the reproduced picture by means of the presence or absence of a decophering function. CONSTITUTION:Picture switches 2 and 9, a converter 3, a quantizing equipment 4, a reverse quantizing equipment 6, reverse converter 7, a frame memory 8 with a movement compensating function, a subtracter 12 and an adder 13 utilize co-relation in a time axial direction, which jointly uses movement compensation for an amination picture, and also encode the animation picture through the use of orthogonal conversion. The high frequency component of an arithmetic result, which is obtained by orthogonal conversion, within the outpus of the quantizing equipment 4 is inputted to a ciphering equipment 5 so as to be enciphered. In the meantime, a low frequency component and side information are multiplexed and outputted together with the enciphered high frequency component without being enciphered. |
