| 摘要 |
<p>PURPOSE:To compress the band of a high band signal to transmit it by using inter-field and inter-frame offset subsampling and time base expansion techniques to compress the transmission band. CONSTITUTION:An input signal is given to a delay circuit 23 and a motion vector detecting circuit 31 through an A/D converter 22. The output of the delay circuit 23 is supplied to not only a subsampling circuit 25 through an inter-field prefilter 24 but also a subsampling circuit 27 through an intra-field prefilter 26. The output of the subsampling circuit 27 is supplied to a RAM 28 through a frame memory 30. Changeover switches 29 and 32 select the output of the subsampling circuit 25 or 27, the RAM 28, or the motion vector detecting circuit 31 and supply it to a time base expanding circuit 33. The output of this circuit 33 and the output of the motion vector detecting circuit 31 are multiplexed in time division by a multiplexing circuit 34 and are transmitted through a D/A converter 35 and a transmission line filter.</p> |
