| 摘要 |
PURPOSE:To suppress the mixing and switching at high band by a chroma signal at mixing without addition and to increase the color reproducibility around the switching boundary, by making the switching control for 2 video signals through the result of comparison between the amplitudes of luminance signal level for two video signals. CONSTITUTION:Color video signals from input terminals 21, 26 are fed to adders 23, 28, control signals F1, F2 are added at adders 23, 28, and color video signals VA, VB are produced and fed to separation circuits 24, 29 and also fed to a switch 30. The chroma component is eliminated from the two video signals VA, VB for the separation circuits 24, 29 and luminance signals VAr, VBr are fed to a comparison circuit 25. Further, at the circuit 25, the luminance level of the luminance signals VAr, VBr is compared, a switching signal S is produced to control a switch 30, and either one of the video signals VA, VB is selected to output a mixed output video signal C to an output terminal 32 via a video clamp circuit 31. |
