| 摘要 |
PURPOSE:To realize an emphasis system which hardly causes picture deterioration with a simple circuit configuration, by restoring a picture signal by performing de-emphasis with a transversal filter with characteristics opposite to those of the pre-emphasis filter. CONSTITUTION:Video input on the transmission side is FM-transmitted through a nonlinear compression circuit 2 after it is subjected to preemphasis by means of the 3-tap transversal filter of a preemphasis filter 1. On the reception side, the video input is passed through the ringing eliminating circuit 4 of a 3-tap transversal filter through a nonlinear expanding circuit 3. Moreover, by cascade- connecting three taps and five taps in a de-emphasis filter 5 and performing de-emphasis by means of the transversal filter of the de-emphasis filter 5 having characteristics opposite to those of the filter 1, picture signals are restored. |
