1. An image processing device that processes an image, comprising: an image input portion inputting a target image that is an image to be processed; a motion vector acquisition portion acquiring a motion vector generated by relative movement with respect to a subject drawn in the target image when an imaging device generates the target image; and a distortion component estimation portion approximating a motion between frames by a matrix that includes only a parallel movement component and a distortion component and estimating a rolling shutter distortion component of the target image based on a parallel movement component the motion vector and the matrix.