| 摘要 |
PURPOSE:To easily correct a color reproduction error by adding the signal, obtained by extracting part of the difference signal of a luminance signal from a red signal and by amplifying only the negative side while removing the positive side, to the difference signal of a red color signal and the luminance signal. CONSTITUTION:Signal R-Y obtained by subtracting luminance signal Y from output R of red signal separating circuit 10 is amplified to obtain A1(R-Y), which is applied to encoder 16 and also applied to positive-side clipping circuit 24 to eliminate its positive side while the negative side is amplified by amplifier 25. This signal is added to signal B-Y obtained by subtracting luminance signal Y from output B of blue signal separating circuit 11 and the sum signal is amplified to obtain A2 (B-Y)', which is processed by encoder 16 together with signals Y and A1(R-Y) to obtain an NTSC signal. Thus, errors of green and cyan large in color reproduction error can be corrected while colors with positive R-Y are not influenced and yellow-green and blue colors small in R-Y among colors with negative R-Y are nearly uninfluenced. |
