A still image of a moving object is restored from portions including the object in an image by using a movement distance of the object during an exposure time and the difference value between output values of adjacent pixels, the movement distance being calculated as a number of pixels. Therefore, especially in cases where a moving bar code is imaged, even if the image of the bar code is blurred as a result of the movement of the bar code during imaging, a still image of the bar code in which the outlines of the black portions and white portions of the bar code are clear can be obtained. Accordingly, bar code information can be read out from the imaged bar code.