1. An image processing device comprising: a distorted image acquiring unit that acquires a distorted image through a photographing operation using a wide-angle lens or an omnidirectional mirror; a cutting reference point setting unit that sets a cutting reference point for cutting a partial cut region from the distorted image; a cut region setting unit that sets the cut region according to the cutting reference point; an eye vector setting unit that sets an eye vector corresponding to the cutting reference point, with a photographing viewpoint of the distorted image as a base point; an offset unit that shifts the cut region by a predetermined distance from the cutting reference point; and an image transforming unit that transforms the shifted cut region through image transformation to transform the distorted image into a planar regular image according to the eye vector.