CIPHER PROCESS SYSTEM FOR COMPOSITE COLOR VIDEO SIGNAL

摘要

PURPOSE:To simplify the compensation of the time shift or the correction of the linearity of the luminance signal by separating the luminance and chroma signals contained in the composite color video signal for the cipher process and then giving the independent control for the luminance and chroma signals at the decoder side. CONSTITUTION:Normal composite color video signal (a) is separated at the transmission side into luminance signal (b) and chroma signal (c) through Y/C isolator circuit 20. Signal (b) is then applied to encoder 21, and encoded luminance signal (d) is generated via the key code given from encoded luminance signal generator 22. And then signal (d) is supplied to matrix circuit 23. Signals (d) and (C) are compounded through circuit 23 and then modulated to transmit encoded composite color video signal (f). This signal (f) is separated into luminance signal (d) and chroma signal (c) through Y/C isolator 26 of the reception side. Then signal (d) is delayed through delay circuit 27 to adjust the time shift to signal (c). Signal (d) sent from circuit 27 is decoded via video processor 28 and then compounded with signal (c) at matrix circuit 29 to then deliver signal (a).