APPARATUS FOR CONTROLLING CONTRAST AND BRIGHTNESS OF DIGITAL VIDEO SIGNAL

摘要

PURPOSE: A controlling apparatus is provided to control contrast and brightness of a video signal in a digital video system, so that the signal is not completely saturated. CONSTITUTION: The controlling apparatus comprises: a first video adjusting unit(210) for adjusting contrast of an inputted video signal according to a prescribed contrast control value; a second video adjusting unit(230) for adjusting brightness of the inputted video signal according to a prescribed brightness control value; a limiter(250) for limiting a level of the video signal adjusted in the first and the second video adjusting units within a constant range; and a mixer(260) for mixing the video signal whose level is limited in the limiter and the inputted video signal. The first and the second video adjusting unit are composed of a multiplier and an adder, respectively.