1. A digital camera, having a function for optically compensating for camera shake, comprising: a movement detector that detects a movement of the digital camera; a movement prediction unit that employs the movement detected by the movement detector to predict a movement of the digital camera after a predetermined period of time has elapsed; an optical system moving unit that moves an optical system of the digital camera so as to compensate for the movement of the digital camera predicted by the movement prediction unit; and an image data correction unit that corrects image data obtained while taking a photograph, based on a difference between an actual movement of the digital camera, which is detected by the movement detector while taking the photograph, and the movement of the digital camera that is predicted, by the movement prediction unit, to occur while taking the photograph, so that the image data will be the same as image data that are obtained when the optical system is moved while taking the photograph in order to compensate for the movement of the digital camera that is detected by the movement detector while actually taking the photograph.