PURPOSE: To realize the optimum emphasis effect with respect to an inputted optional video luminance signal.

CONSTITUTION: A band pass filter 4 is used to extract only a high frequency component only from an input of an optional video luminance signal. The quantity of the component is converted into a high/low level of a bias with a bias conversion circuit 5. Furthermore, a variable resistor 1 deciding the degree of emphasis of a horizontal emphasis circuit is controlled by an adjustment circuit 6 in response to the high and low level of the bias. Thus, the optimum emphasis effect is realized automatically with respect to the input of an optional luminance signal to attain higher picture quality.