| 摘要 |
PURPOSE:To effectively emphasize a part where the color is clear in a picture to obtain a color picture abundant in coloring by emphasizing the level of a brightness signal by a prescribed amplification ratio when the total area of the part of a picture having the color beyond a prescribed level is larger than a reference area. CONSTITUTION:The total area of the picture-parts of a color in a level beyond the prescribed level is calculated based on a color difference signal in a video signal, and compared with the reference area. In case the said area is larger than the reference area, the level of the brightness signal is emphasized by the prescribed amplification ratio. For instance, both color difference signals ER-Y and EB-Y are compared with comparison reference voltages Ea-Ed by comparators 14-20. The first comparator 14, the second one 16, the third one 18, and the fourth one 20 respectively generates a specific output voltage. And the output voltage can be obtained from the output terminal of an OR gate 26, which is applied with time-integration by an integral circuit 28. The resulting voltage is compared with the comparison reference voltage E by a comparator 30. Consequently, a clock pulse CK is gated by an AND gate 32 by using the square wave voltage.
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