An image in a field inputted by interlace scanning is delayed for a time period corresponding to one field, then, by comparing the delayed image signals and the not-delayed image signals of the image, a movement detecting unit determines whether the input image is a moving image or a still image and outputs a signal indicating the determined result. A selecting unit which includes an image combining unit combines the delayed image signals and the not-delayed image signals, and selects either the combined image signals or not-combined image signals on the basis of the detected result by the movement detecting unit. Accordingly, the image signals realizing a high quality image displayed on a multimedia device are obtained.