A buffer delays an input luminance signal by a 1-frame period. A screen unit motion detection section determines whether an image indicated by the input luminance signal is a moving image or a static image by a screen unit, and outputs a gradual determination result from the static image to the moving image. A subtracter outputs a differential signal obtained by subtracting the input luminance signal from the luminance signal delayed by the 1-frame period. A pixel unit motion detector detects motion of a pixel unit and outputs a detection result by using a plurality of level values within a predetermined range. A limiter limits the differential signal in accordance with the determination result of the screen unit motion detector. An adder adds an output signal of the multiplier and the input luminance signal together.