PURPOSE: To make an input color picture clear by converting red, green and blue color picture signals to a luminance signal and a chrominance signal, obtaining an emphasis function to the respective luminance level of the luminance signal and executing emphasis processing to the respective picture signals.

CONSTITUTION: A chrominance signal converting circuit 4 takes out the luminance signal from the RGB color picture signals, which are composed of the three signals of a red signal (R), green signal (G) and blue signal (B), and obtains the emphasis function to the respective luminance levels by an emphasis function computing circuit 5. Next, by using the obtained emphasis function, and R signal emphasizing circuit 6 executes the emphasis of the R signal, a G signal emphasizing circuit 7 executes the emphasis of the G signal and a B signal emphasizing circuit 8 executes the emphasis of the B signal respectively. Thus, in correspondence to the character of the input color picture, a detail signal can be adaptively emphasized and the input color picture can be made clear.